# OUTPUT FROM GHIDRA WITH WASM EXTENSION:
#
# byte export::check_flag(void)
# {
#   int strcmp_result;
#   int j;
#   int i;
#   undefined1 c;
#
#   for (i = 0; (&ram_result_buf)[i] != '\0'; i = i + 1) {
#     (&ram_result_buf)[i] = (&ram_result_buf)[i] ^ 0x14;
#     if (0 < i) {
#       (&ram_result_buf)[i] = (&ram_result_buf)[i] ^ (&DA T_ram_0000042f)[i];
#     }
#     if (2 < i) {
#       (&ram_result_buf)[i] = (&ram_result_buf)[i] ^ (&DA T_ram_0000042d)[i];
#     }
#     (&ram_result_buf)[i] = (&ram_result_buf)[i] ^ (byte) (i % 10);
#     if (i % 2 == 0) {
#       (&ram_result_buf)[i] = (&ram_result_buf)[i] ^ 9;
#     }
#     else {
#       (&ram_result_buf)[i] = (&ram_result_buf)[i] ^ 8;
#     }
#     if (i % 3 == 0) {
#       (&ram_result_buf)[i] = (&ram_result_buf)[i] ^ 7;
#     }
#     else if (i % 3 == 1) {
#       (&ram_result_buf)[i] = (&ram_result_buf)[i] ^ 6;
#     }
#     else {
#       (&ram_result_buf)[i] = (&ram_result_buf)[i] ^ 5;
#     }
#   }
#   for (j = 0; j < i; j = j + 1) {
#     if ((j % 2 == 0) && (j + 1 < i)) {
#       c = (&ram_result_buf)[j];
#       (&ram_result_buf)[j] = (&ram_result_buf_plus1)[j];
#       (&ram_result_buf_plus1)[j] = c;
#     }
#   }
#   strcmp_result = strcmp((char *)0x400,&ram_result _buf);
#   return (strcmp_result != 0 ^ 0xffU) & 1;
# }

INPUT_0400 = b"\x18j|a\x118i7\x1fYyY>\x1cVc\x0dB\x1d~l9\x1cZ!]c\x11\x00b\x05IK~a4\x1cW(\x0fR"

def check_flag(flag: bytes) -> bool:
    ram_result_buf = bytearray(flag)
    i = 0
    while i < len(ram_result_buf) and ram_result_buf[i] != 0:
        ram_result_buf[i] ^= 0x14

        if i > 0:
            ram_result_buf[i] ^= ram_result_buf[i - 1]

        if i > 2:
            ram_result_buf[i] ^= ram_result_buf[i - 3]

        ram_result_buf[i] ^= (i % 10)

        if i % 2 == 0:
            ram_result_buf[i] ^= 9
        else:
            ram_result_buf[i] ^= 8

        if i % 3 == 0:
            ram_result_buf[i] ^= 7
        elif i % 3 == 1:
            ram_result_buf[i] ^= 6
        else:
            ram_result_buf[i] ^= 5

        i += 1

    for j in range(len(ram_result_buf)):
        if (j % 2 == 0) and (j + 1 < i):
          ram_result_buf[j], ram_result_buf[j + 1] = ram_result_buf[j + 1], ram_result_buf[j]

    return bytes(ram_result_buf) == INPUT_0400

def recover_flag() -> bytes:
    recovered_flag = bytearray(INPUT_0400)

    for j in range(0, len(recovered_flag)):
        if (j % 2 == 0) and (j + 1 < len(recovered_flag)):
            recovered_flag[j], recovered_flag[j + 1] = recovered_flag[j + 1], recovered_flag[j]

    for i in reversed(range(len(recovered_flag))):
        if i % 3 == 0:
            recovered_flag[i] ^= 7
        elif i % 3 == 1:
            recovered_flag[i] ^= 6
        else:
            recovered_flag[i] ^= 5

        if i % 2 == 0:
            recovered_flag[i] ^= 9
        else:
            recovered_flag[i] ^= 8

        recovered_flag[i] ^= (i % 10)

        if i > 2:
            recovered_flag[i] ^= recovered_flag[i - 3]

        if i > 0:
            recovered_flag[i] ^= recovered_flag[i - 1]

        recovered_flag[i] ^= 0x14

    return bytes(recovered_flag)

def main():
    flag = recover_flag()
    print(f"Recovered flag: {flag.decode()}")

if __name__ == "__main__":
    main()