(define (max2 xs)
  (foldr max
         (car xs)
         (cdr xs)))

(define (zipWith op xs ys)
  (if (or (null? xs) (null? ys))
      '()
      (cons (op (car xs) (car ys))
            (zipWith op (cdr xs) (cdr ys)))))

(define (zipWith4 op xs ys zs ts)
  (zipWith op (zipWith op (zipWith op xs ys) zs) ts))

(define (drop n xs)
  (if (or (zero? n) (null? xs))
      xs
      (drop (- n 1) (cdr xs))))

(define (g x y z xs)
  (zipWith4 *
            xs
            (drop x xs)
            (drop y xs)
            (drop z xs)))

(define (solution xs)
  (max2 (append (g 20 40 60 xs)
                (g  1  2  3 xs)
                (g 21 42 63 xs)
                (g 19 38 57 xs))))

(solution (list  8  2 22 97 38 15  0 40  0 75  4  5  7 78 52 12 50 77 91  8
                49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48  4 56 62  0
                81 49 31 73 55 79 14 29 93 71 40 67 53 88 30  3 49 13 36 65
                52 70 95 23  4 60 11 42 69 24 68 56  1 32 56 71 37  2 36 91
                22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
                24 47 32 60 99  3 45  2 44 75 33 53 78 36 84 20 35 17 12 50
                32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70
                67 26 20 68  2 62 12 20 95 63 94 39 63  8 40 91 66 49 94 21
                24 55 58  5 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72
                21 36 23  9 75  0 76 44 20 45 35 14  0 61 33 97 34 31 33 95
                78 17 53 28 22 75 31 67 15 94  3 80  4 62 16 14  9 53 56 92
                16 39  5 42 96 35 31 47 55 58 88 24  0 17 54 24 36 29 85 57
                86 56  0 48 35 71 89  7  5 44 44 37 44 60 21 58 51 54 17 58
                19 80 81 68  5 94 47 69 28 73 92 13 86 52 17 77  4 89 55 40
                 4 52  8 83 97 35 99 16  7 97 57 32 16 26 26 79 33 27 98 66
                88 36 68 87 57 62 20 72  3 46 33 67 46 55 12 32 63 93 53 69
                 4 42 16 73 38 25 39 11 24 94 72 18  8 46 29 32 40 62 76 36
                20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74  4 36 16
                20 73 35 29 78 31 90  1 74 31 49 71 48 86 81 16 23 57  5 54
                 1 70 54 71 83 51 54 69 16 92 33 48 61 43 52  1 89 19 67 48))