diff --git a/day07/default.nix b/day07/default.nix
new file mode 100644
index 0000000..c248290
--- /dev/null
+++ b/day07/default.nix
@@ -0,0 +1,71 @@
+{ pkgs, lib }:
+
+with lib;
+
+let
+  updateState = s@{ path ? [], filetree ? { } }: line: let
+      splitCommand = splitString " " line;
+    in if line == "$ cd /" then { path = [ "/" ]; inherit filetree; }
+    else if line == "$ cd .." then { path = init path; inherit filetree; }
+    else if elemAt splitCommand 1 == "cd" then { path = path ++ [(elemAt splitCommand 2)]; inherit filetree; }
+    else if line == "$ ls" then s
+    else if head splitCommand == "dir" then s
+    else let
+      newPath = path ++ [(elemAt splitCommand 1)];
+      filesize = toInt (elemAt splitCommand 0);
+    in {
+      inherit path;
+      filetree = recursiveUpdate filetree (setAttrByPath newPath filesize);
+    };
+
+    mapAttrsRecursiveToList = f: g: attrs: let
+      inner = path: attrs': flatten (mapAttrsToList (attrsToListF path) attrs');
+      attrsToListF = path: n: v: let newPath = path ++ [n];
+                                 in if isAttrs v
+                                      then g newPath (inner newPath v)
+                                      else f newPath v;
+    in inner [] attrs;
+
+    backfillDirSizes = { path, size }: dirs:
+      if path == []
+        then dirs
+        else let
+               key = concatStringsSep "/" path;
+               newDirs = recursiveUpdate dirs { ${key} = (dirs.${key} or 0) + size; };
+             in backfillDirSizes { path = init path; inherit size; } newDirs;
+
+    mapFiletreeToDirSizes = attrs: pipe attrs [
+      (mapAttrsRecursiveToList (path: size: { inherit path size; }) (_: v: v))
+      (map (x: x // { path = init x.path; }))
+      (fold backfillDirSizes {})
+    ];
+
+    dirSizes = pipe ./input.txt [
+      fileContents
+      (splitString "\n")
+      (foldl updateState { })
+      (x: x.filetree)
+      mapFiletreeToDirSizes
+    ];
+
+    answer1 = pipe dirSizes [
+      (filterAttrs (_: v: v <= 100000))
+      attrValues
+      (foldr add 0)
+      toString
+    ];
+
+    answer2 = pipe dirSizes [
+      (filterAttrs (_: v: v >= dirSizes."/" - 40000000))
+      attrValues
+      (foldr min (30000000))
+      toString
+    ];
+
+in pkgs.writeText "answers" ''
+  Task1:
+    ${answer1}
+
+  Task2:
+    ${answer2}
+''
diff --git a/day07/input.txt b/day07/input.txt
new file mode 100644
index 0000000..eb1855d
--- /dev/null
+++ b/day07/input.txt
@@ -0,0 +1,1030 @@
+$ cd /
+$ ls
+dir drblq
+133789 fjf
+dir jpfrhmw
+dir jqfwd
+dir ncgffsr
+12962 ntnr.lrq
+dir qnbq
+dir rqdngnrq
+dir shcvnqq
+dir vsd
+dir vtzvf
+$ cd drblq
+$ ls
+133843 bglzqdd
+dir brfnfhj
+268201 fbqjmp.jzv
+80676 shcvnqq
+$ cd brfnfhj
+$ ls
+150447 jlcg.dsg
+dir nhvgrzs
+$ cd nhvgrzs
+$ ls
+282889 jlcg.dsg
+19004 ncgffsr.gwr
+dir vbzr
+6338 vpsgdph.gbh
+dir wdcn
+$ cd vbzr
+$ ls
+225101 fbqjmp
+243277 vbzr
+$ cd ..
+$ cd wdcn
+$ ls
+154089 dlmpbbf.psv
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd jpfrhmw
+$ ls
+87622 cffdsj.jzf
+26165 qnbq.sbm
+dir vbzr
+$ cd vbzr
+$ ls
+dir blhstw
+16919 nttftcts
+dir rgdp
+116477 shcvnqq
+242592 tmjrnqbz.chq
+dir vbzr
+dir wmct
+$ cd blhstw
+$ ls
+98023 jwdv.qct
+$ cd ..
+$ cd rgdp
+$ ls
+dir gcb
+141507 shcvnqq
+dir ssvzm
+$ cd gcb
+$ ls
+189016 ncgffsr.rbq
+$ cd ..
+$ cd ssvzm
+$ ls
+82667 shcvnqq.zjq
+$ cd ..
+$ cd ..
+$ cd vbzr
+$ ls
+120202 jlcg.dsg
+86205 vbzr.jtr
+$ cd ..
+$ cd wmct
+$ ls
+dir fbsfcgph
+155709 hpsftv
+13636 lztgs
+273353 ncgffsr.jsg
+dir pvwhpfp
+$ cd fbsfcgph
+$ ls
+139944 ncgffsr.gpf
+$ cd ..
+$ cd pvwhpfp
+$ ls
+111230 bscrjpzh.glp
+dir dgjsddgq
+37234 lwd
+107139 lztgs
+258111 mgtwwvwz
+117638 qpdvnfb.gnf
+dir szrplcdw
+dir vzsl
+dir wsmf
+$ cd dgjsddgq
+$ ls
+dir qnbq
+$ cd qnbq
+$ ls
+199119 jlcg.dsg
+$ cd ..
+$ cd ..
+$ cd szrplcdw
+$ ls
+122236 qclr.cpf
+269638 qnbq
+$ cd ..
+$ cd vzsl
+$ ls
+233006 twpz.tdm
+$ cd ..
+$ cd wsmf
+$ ls
+dir wcnptvtz
+$ cd wcnptvtz
+$ ls
+183952 shcvnqq.lwt
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd jqfwd
+$ ls
+dir hqb
+285121 jqffsjbs.jrm
+dir nhpqpdn
+dir qnbq
+dir qtrv
+dir wspztvjr
+$ cd hqb
+$ ls
+253786 jwdv.qct
+dir vbzr
+$ cd vbzr
+$ ls
+153 gbh
+dir gqpqqrgl
+dir jzncgd
+36914 nvdnsnls.mpd
+$ cd gqpqqrgl
+$ ls
+206691 dmdgcwm.bgh
+$ cd ..
+$ cd jzncgd
+$ ls
+122640 vrgmf.tnp
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd nhpqpdn
+$ ls
+86329 ntnr.lrq
+$ cd ..
+$ cd qnbq
+$ ls
+76269 fbqjmp.lbd
+118968 fbqjmp.msg
+190416 gfwhsb.dpc
+dir lhgjrmj
+dir pbv
+173541 pfl
+141842 srrmt.ssj
+$ cd lhgjrmj
+$ ls
+dir ghccnw
+180420 ldzcj.rwz
+149356 lztgs
+61792 ncgffsr
+dir spmbcjhc
+$ cd ghccnw
+$ ls
+253233 lztgs
+56439 ntnr.lrq
+19225 ntrmjf.gdb
+31628 pdhhzjhm.lbd
+$ cd ..
+$ cd spmbcjhc
+$ ls
+dir shcvnqq
+$ cd shcvnqq
+$ ls
+122334 drjbh
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd pbv
+$ ls
+69436 cctsjqh.wqr
+285573 ljtqddz
+$ cd ..
+$ cd ..
+$ cd qtrv
+$ ls
+234568 dmwqfbwd
+dir pwwsrjc
+245046 qmcr
+159151 qtvdjncm.rdb
+dir swhzds
+178915 vbzr.vgn
+dir vcgv
+$ cd pwwsrjc
+$ ls
+173975 bgdj.jnw
+202714 jwdv.qct
+270702 wggrgcvw.rtp
+$ cd ..
+$ cd swhzds
+$ ls
+114686 jwdv.qct
+$ cd ..
+$ cd vcgv
+$ ls
+dir fbqjmp
+dir qlsgtfhf
+dir vbzr
+$ cd fbqjmp
+$ ls
+73065 fbqjmp.jfb
+dir shcvnqq
+$ cd shcvnqq
+$ ls
+231428 shcvnqq
+$ cd ..
+$ cd ..
+$ cd qlsgtfhf
+$ ls
+75227 ntnr.lrq
+$ cd ..
+$ cd vbzr
+$ ls
+128050 ncgffsr.gsj
+187649 vbzr
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd wspztvjr
+$ ls
+dir pntrhtwh
+dir qnbq
+dir zfdzvv
+$ cd pntrhtwh
+$ ls
+237258 cffhtr
+$ cd ..
+$ cd qnbq
+$ ls
+dir qnbq
+$ cd qnbq
+$ ls
+dir ccwmftsj
+$ cd ccwmftsj
+$ ls
+dir mfc
+dir shcvnqq
+12262 smpjmn
+$ cd mfc
+$ ls
+198047 fbqjmp.cgh
+dir gghsht
+205411 wlclz
+$ cd gghsht
+$ ls
+31767 vbzr.lmb
+$ cd ..
+$ cd ..
+$ cd shcvnqq
+$ ls
+dir lgrghwf
+$ cd lgrghwf
+$ ls
+114786 shcvnqq.vrz
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd zfdzvv
+$ ls
+54298 sjp
+60303 tcmhrll.htm
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ncgffsr
+$ ls
+dir fqqsqmpr
+dir gfznw
+dir ncdft
+dir pwmppt
+dir shcvnqq
+196969 vbzr
+214841 vzgvr
+$ cd fqqsqmpr
+$ ls
+dir mcdjcntr
+$ cd mcdjcntr
+$ ls
+281856 ncgffsr.lbm
+$ cd ..
+$ cd ..
+$ cd gfznw
+$ ls
+255657 fzrctbsj.lgf
+dir ltfsndpd
+175434 qnbq
+31794 qnbq.zhd
+13366 shcvnqq.wld
+dir vcspqgn
+235199 wmnjjd.bnh
+dir wqpnp
+$ cd ltfsndpd
+$ ls
+dir ncgffsr
+dir zpzvdhb
+$ cd ncgffsr
+$ ls
+9898 jjbsnj.gcg
+$ cd ..
+$ cd zpzvdhb
+$ ls
+106139 lnp
+$ cd ..
+$ cd ..
+$ cd vcspqgn
+$ ls
+25386 dgsmmqj
+$ cd ..
+$ cd wqpnp
+$ ls
+65905 wjtbfvjp.fmd
+$ cd ..
+$ cd ..
+$ cd ncdft
+$ ls
+34616 bzlpmsqc
+59863 jlcg.dsg
+64629 zpzjcl.fmp
+$ cd ..
+$ cd pwmppt
+$ ls
+dir dwnqgrzm
+80901 vbzr.vsg
+89557 vbzr.zlz
+$ cd dwnqgrzm
+$ ls
+184770 jwdv.qct
+dir vbzr
+$ cd vbzr
+$ ls
+210329 jlcg.dsg
+62272 jwdv.qct
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd shcvnqq
+$ ls
+128433 gbh
+30208 hjbw
+200071 jlcg.dsg
+dir sgcz
+25045 tbhlwfqg.hts
+$ cd sgcz
+$ ls
+193481 gbh
+96461 jwdv.qct
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd qnbq
+$ ls
+236171 shcvnqq
+$ cd ..
+$ cd rqdngnrq
+$ ls
+dir cprnb
+280135 hshsfqwm
+dir hwhm
+245626 qnbq
+145502 qspgdz
+114231 rctg.tgt
+dir zgn
+$ cd cprnb
+$ ls
+115025 twwgmmp.wbb
+$ cd ..
+$ cd hwhm
+$ ls
+229849 cvm
+190622 jwdv.qct
+dir mscztz
+dir ncgffsr
+$ cd mscztz
+$ ls
+59743 bzgpzn.bds
+75184 pbdgv
+181089 shcvnqq.dhq
+dir zqgtr
+$ cd zqgtr
+$ ls
+189142 ffnznfs.nct
+$ cd ..
+$ cd ..
+$ cd ncgffsr
+$ ls
+dir dphrnjl
+dir zzfztql
+$ cd dphrnjl
+$ ls
+117317 vbzr
+$ cd ..
+$ cd zzfztql
+$ ls
+51096 lztgs
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd zgn
+$ ls
+dir bpbzwgz
+dir gqnw
+75631 ljptj
+283351 ljzhsw.rbs
+131158 lztgs
+dir ncgffsr
+3136 nnpl.swf
+dir shcvnqq
+dir vbzr
+$ cd bpbzwgz
+$ ls
+29659 jlcg.dsg
+15547 shcvnqq
+117389 zprhsdfv
+$ cd ..
+$ cd gqnw
+$ ls
+117091 brqwhst.jgb
+88406 nzjmbrrm.hmh
+$ cd ..
+$ cd ncgffsr
+$ ls
+195821 gbh
+dir lbzgc
+226692 llqqr.spq
+247989 lztgs
+231909 vnctc
+157973 wqnggh
+$ cd lbzgc
+$ ls
+251414 ffmsbscc.dqg
+46840 lztgs
+$ cd ..
+$ cd ..
+$ cd shcvnqq
+$ ls
+dir dvvmhzcq
+dir ncgffsr
+dir sqzzllv
+$ cd dvvmhzcq
+$ ls
+dir qnbq
+70226 qvvm.rpp
+dir shcvnqq
+$ cd qnbq
+$ ls
+103994 bfcjrmvr.ltq
+dir fbqjmp
+dir fcs
+177152 gjghvvw.bzg
+dir lbfjqh
+78412 ntnr.lrq
+dir sgjtm
+286995 shcvnqq
+51750 wmq.vjj
+$ cd fbqjmp
+$ ls
+267212 qhhb.zvg
+$ cd ..
+$ cd fcs
+$ ls
+272051 znhsswwh.mjj
+$ cd ..
+$ cd lbfjqh
+$ ls
+261487 jlcg.dsg
+$ cd ..
+$ cd sgjtm
+$ ls
+dir dnznpj
+dir jzsntnbs
+dir nqgcbd
+dir vdg
+$ cd dnznpj
+$ ls
+173938 hrp.cjq
+180485 qnbq.thj
+215400 ztvt.wnt
+$ cd ..
+$ cd jzsntnbs
+$ ls
+67448 gpvgh.psg
+$ cd ..
+$ cd nqgcbd
+$ ls
+196250 fbqjmp.qcv
+198482 jlcg.dsg
+$ cd ..
+$ cd vdg
+$ ls
+257343 jwdv.qct
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd shcvnqq
+$ ls
+156769 fbqjmp.hdb
+$ cd ..
+$ cd ..
+$ cd ncgffsr
+$ ls
+205473 fbqjmp
+113067 gsvznzz.qtv
+$ cd ..
+$ cd sqzzllv
+$ ls
+146018 ddvjgswr.gsq
+$ cd ..
+$ cd ..
+$ cd vbzr
+$ ls
+dir vbzr
+$ cd vbzr
+$ ls
+266721 mhlfqpbs.pwr
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd shcvnqq
+$ ls
+dir slnvdd
+$ cd slnvdd
+$ ls
+90875 pzqv.gnv
+207484 rbrj.vcr
+$ cd ..
+$ cd ..
+$ cd vsd
+$ ls
+dir dfb
+dir fqqnsph
+dir gbwdhjr
+18837 jwdv.qct
+dir ncgffsr
+dir qnbq
+dir rjzjrbvs
+$ cd dfb
+$ ls
+dir bpst
+66174 jwdv.qct
+dir lcwhfzjw
+$ cd bpst
+$ ls
+dir nqftnn
+dir pcvgnvnp
+$ cd nqftnn
+$ ls
+dir bbrsg
+dir gjfc
+dir hfql
+dir shcvnqq
+139226 shcvnqq.sbd
+dir ssnjqbg
+$ cd bbrsg
+$ ls
+73382 vjcf
+$ cd ..
+$ cd gjfc
+$ ls
+164310 gbh
+126316 mmqnrc
+133899 ntnr.lrq
+102615 rgfhrt
+$ cd ..
+$ cd hfql
+$ ls
+14685 jwdv.qct
+$ cd ..
+$ cd shcvnqq
+$ ls
+119597 lztgs
+34165 shcvnqq.zcg
+$ cd ..
+$ cd ssnjqbg
+$ ls
+77678 gqdfbqj.tmj
+$ cd ..
+$ cd ..
+$ cd pcvgnvnp
+$ ls
+21250 lhq
+266619 qps.crp
+$ cd ..
+$ cd ..
+$ cd lcwhfzjw
+$ ls
+dir bhdnnbvm
+dir fdnsvfh
+12002 jlcg.dsg
+dir lfdbzfl
+46488 ncgffsr
+233704 nthcv.pnc
+204660 ntnr.lrq
+172482 shcvnqq
+dir tlw
+$ cd bhdnnbvm
+$ ls
+37204 fwrdjw.zvv
+3248 ntnr.lrq
+$ cd ..
+$ cd fdnsvfh
+$ ls
+20765 jlfgnwb.szl
+$ cd ..
+$ cd lfdbzfl
+$ ls
+dir fspntmld
+183925 jlcg.dsg
+$ cd fspntmld
+$ ls
+251568 lztgs
+146785 ncgffsr.mmj
+$ cd ..
+$ cd ..
+$ cd tlw
+$ ls
+dir qqn
+$ cd qqn
+$ ls
+39232 lprqfwf
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd fqqnsph
+$ ls
+132318 lztgs
+103863 ntnr.lrq
+18793 tngbs
+$ cd ..
+$ cd gbwdhjr
+$ ls
+253798 jwdv.qct
+$ cd ..
+$ cd ncgffsr
+$ ls
+110767 blctz.tqz
+dir csfssn
+dir dbbfz
+dir hjgm
+dir hwd
+249139 rgcz.gnz
+dir wgw
+$ cd csfssn
+$ ls
+dir dlcw
+dir jqspd
+119066 mlwlc.mql
+dir ncgffsr
+203475 nwnbsc
+143071 qnbq
+116623 qvw.gjz
+83637 whm.cdg
+$ cd dlcw
+$ ls
+232066 gqllsd.qpl
+1046 mfsh
+$ cd ..
+$ cd jqspd
+$ ls
+251070 mthmm.bmh
+$ cd ..
+$ cd ncgffsr
+$ ls
+83639 ntnr.lrq
+$ cd ..
+$ cd ..
+$ cd dbbfz
+$ ls
+112576 jgqf.qmj
+148549 jlcg.dsg
+144811 jwdv.qct
+23726 ntnr.lrq
+123802 pgdjchrf.vnm
+dir vzfbzbcp
+$ cd vzfbzbcp
+$ ls
+39375 fbqq
+31914 jwdv.qct
+165999 lztgs
+$ cd ..
+$ cd ..
+$ cd hjgm
+$ ls
+dir ljqjtdmf
+100534 mdw
+219057 qnbq
+97164 rzjwmvdw.vlv
+dir shcvnqq
+83034 vbzr
+$ cd ljqjtdmf
+$ ls
+23716 dmslzv.qns
+159519 gbh
+dir hlvbmpg
+dir nlqqshp
+247315 vqt
+dir wlsjnthg
+$ cd hlvbmpg
+$ ls
+54421 jlcg.dsg
+$ cd ..
+$ cd nlqqshp
+$ ls
+dir rvzprwhp
+$ cd rvzprwhp
+$ ls
+35024 lztgs
+$ cd ..
+$ cd ..
+$ cd wlsjnthg
+$ ls
+29178 gnrlgb.bgh
+$ cd ..
+$ cd ..
+$ cd shcvnqq
+$ ls
+150311 nvrd
+$ cd ..
+$ cd ..
+$ cd hwd
+$ ls
+dir jzqtmm
+$ cd jzqtmm
+$ ls
+103547 jtvdt.jtn
+$ cd ..
+$ cd ..
+$ cd wgw
+$ ls
+dir mmhlt
+$ cd mmhlt
+$ ls
+dir cmwjh
+$ cd cmwjh
+$ ls
+243844 qnbq.shn
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd qnbq
+$ ls
+dir dhfng
+dir fbqjmp
+16855 rgrszmrh.lbl
+dir rqjs
+dir shcvnqq
+38322 vhvrmq
+$ cd dhfng
+$ ls
+132537 gwngz.hpt
+dir lbccc
+182221 ntnr.lrq
+$ cd lbccc
+$ ls
+282448 fbqjmp.njj
+267049 gbh
+dir jtj
+dir ntnn
+dir vbfgmmvw
+128500 vbzr
+$ cd jtj
+$ ls
+dir hvmlh
+$ cd hvmlh
+$ ls
+131886 dmww.sqc
+$ cd ..
+$ cd ..
+$ cd ntnn
+$ ls
+109064 lgh.bbf
+dir wfgdd
+53862 wflv.ngc
+$ cd wfgdd
+$ ls
+58756 gbh
+dir lgzlndn
+dir qnbq
+$ cd lgzlndn
+$ ls
+190415 dwsqvczd
+$ cd ..
+$ cd qnbq
+$ ls
+240922 znjhmhp.ngt
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd vbfgmmvw
+$ ls
+271827 vbzr.dfl
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd fbqjmp
+$ ls
+144993 gvpnf
+150786 jwdv.qct
+49025 pdcwwtt.grs
+$ cd ..
+$ cd rqjs
+$ ls
+dir bwnzs
+119390 jlcg.dsg
+172042 vjzg
+$ cd bwnzs
+$ ls
+108537 hzzgm.zrn
+38699 qgfqbfr
+dir vhvcfhvr
+$ cd vhvcfhvr
+$ ls
+2783 jwdv.qct
+209933 mgj.nvj
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd shcvnqq
+$ ls
+257312 fbqjmp
+193792 msdqtrpn.grn
+98165 rgm
+$ cd ..
+$ cd ..
+$ cd rjzjrbvs
+$ ls
+dir ftrlfg
+dir mtrnl
+dir rdpbbd
+dir shcvnqq
+dir vztnr
+$ cd ftrlfg
+$ ls
+196590 cjjvwjb
+dir ffsvh
+70123 ldnbc
+dir lwnfc
+106499 lztgs
+dir ncgffsr
+dir tfdctq
+dir vgthdbf
+80852 zndjt.wtl
+$ cd ffsvh
+$ ls
+20370 dvdftpvb.qcj
+$ cd ..
+$ cd lwnfc
+$ ls
+dir fgmd
+dir gmdjt
+274331 hmgjmq.vbz
+9726 qjfdqbf.dfj
+dir ssnncn
+$ cd fgmd
+$ ls
+280608 jwdv.qct
+201912 rqtbw.shd
+$ cd ..
+$ cd gmdjt
+$ ls
+202107 jwdv.qct
+$ cd ..
+$ cd ssnncn
+$ ls
+140697 jwdv.qct
+$ cd ..
+$ cd ..
+$ cd ncgffsr
+$ ls
+227389 fpdfqp.fzl
+164141 hzhrrvpm.hlf
+$ cd ..
+$ cd tfdctq
+$ ls
+dir cttmzlw
+dir ntvtm
+257094 qnbq.zjm
+284928 shcvnqq
+$ cd cttmzlw
+$ ls
+142651 rptschdv.mgv
+$ cd ..
+$ cd ntvtm
+$ ls
+176269 dhpj
+88278 gbh
+$ cd ..
+$ cd ..
+$ cd vgthdbf
+$ ls
+130998 ncgffsr.mnf
+$ cd ..
+$ cd ..
+$ cd mtrnl
+$ ls
+86144 djwnvdj
+122600 gsdpwh.cmb
+$ cd ..
+$ cd rdpbbd
+$ ls
+177384 gbh
+dir gstfdm
+dir qnbq
+dir qtj
+260302 vbzr.dhq
+$ cd gstfdm
+$ ls
+23734 mnwzrm.hzr
+$ cd ..
+$ cd qnbq
+$ ls
+51705 gmt
+205537 ntnr.lrq
+94469 vbzr.bvj
+$ cd ..
+$ cd qtj
+$ ls
+dir tls
+dir zvpcfhg
+$ cd tls
+$ ls
+dir chvgwnt
+dir jvgnmfjw
+$ cd chvgwnt
+$ ls
+dir rbw
+dir srhj
+$ cd rbw
+$ ls
+174372 btjd.bvv
+272995 cnqqh.dfc
+$ cd ..
+$ cd srhj
+$ ls
+134054 qwzpr
+$ cd ..
+$ cd ..
+$ cd jvgnmfjw
+$ ls
+dir hdcwbwgm
+236775 sdc
+$ cd hdcwbwgm
+$ ls
+113707 ntnr.lrq
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd zvpcfhg
+$ ls
+dir lsq
+$ cd lsq
+$ ls
+220331 jlcg.dsg
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd shcvnqq
+$ ls
+dir cmwrqgfq
+258731 fbqjmp.fvn
+277895 gbh
+64973 jlcg.dsg
+77978 jwdv.qct
+dir lttjrdn
+dir sqgnhc
+$ cd cmwrqgfq
+$ ls
+81199 gbh
+$ cd ..
+$ cd lttjrdn
+$ ls
+23355 gbh
+148263 hcgfqdw
+57338 hjwr
+166510 jbvnmcj
+$ cd ..
+$ cd sqgnhc
+$ ls
+dir glswqrdp
+dir qnbq
+$ cd glswqrdp
+$ ls
+225761 ncgffsr.vct
+$ cd ..
+$ cd qnbq
+$ ls
+62861 pdqz.wzs
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd vztnr
+$ ls
+189943 wvtlfsp
+$ cd ..
+$ cd ..
+$ cd ..
+$ cd vtzvf
+$ ls
+43248 jwdv.qct
diff --git a/flake.nix b/flake.nix
index f7620e5..7b48120 100644
--- a/flake.nix
+++ b/flake.nix
@@ -12,6 +12,7 @@
       day04 = pkgs.callPackage ./day04 { };
       day05 = pkgs.callPackage ./day05 { };
       day06 = pkgs.callPackage ./day06 { };
+      day07 = pkgs.callPackage ./day07 { };
     };
   };
 }