# project euler 62
# [all cube permutations smaller than cube] ? cube
Chain ← ▽⤚≡⌟(≍⍆⊥10)⊙(⍆⊥10)⊸(
  ▽⤚≡(≤⧻⊥10) ⊙(⧻⊥10)⊸⍜°ⁿ₃(⇡⌈)
)

⍢+₁(<4⧻Chainⁿ3) 1
⊢Chainⁿ3