val .isCusip = fn(.s) { if .s is not string or len(.s) != 9 { return false } val .sum = for[=0] .i of 8 { val .c = .s[.i] var .v = 0 switch[and] .c { case >= '0', <= '9': .v = .c-'0' case >= 'A', <= 'Z': .v = .c-55 # .c-'A'+10 case '*': .v = 36 case '@': .v = 37 case '#': .v = 38 default: return false } if .i div 2: .v *= 2 _for += .v \ 10 + .v rem 10 } .s[9]-'0' == (10-(.sum rem 10)) rem 10 } val .candidates = w/037833100 17275R102 38259P508 594918104 68389X106 68389X105/ for .c in .candidates { writeln .c, ": ", if(.isCusip(.c): "good" ; "bad") }