⍝ Two Suboptimal Solutions
solution ← ⊃×/∘(¯1↓⍳∘≢⌽¨⊂)       ⍝ Using rotates
solution ← ×/¨((↓∘.≠⍨∘⍳∘≢)⊢⍤/¨⊂) ⍝ Using filters (compresses)

⍝ The Actual Solution
solution ← ×/÷⊢

⍝ Tests
solution 5 2 1 4 3 ⍝ 24 60 120 30 40
solution 2 1 4 3   ⍝ 12 24 6 8