{⎕←'Input:',⍺,⍵ ⋄ ⍺+⍵}/ 1 2 3 4 5
Input: 4 5
Input: 3 9
Input: 2 12
Input: 1 14
15
      {⎕←'Input:',⍺,⍵ ⋄ ⍺+⍵}/ 1
1
      {⎕←'Input:',⍺,⍵ ⋄ ⍺+⍵}/ ⍬
DOMAIN ERROR