1  input ← ⍎¨','(≠⊆⊢)⊃⊃⎕NGET '../.cache/2021/7' 1
2  ⎕ ← ⌊/{+/|¨⍵-input}¨⍳≢input
3  ⎕ ← ⌊/{+/(+/⍳)¨|¨⍵-input}¨⍳≢input