old_contents: def largest_grid_product(grid):
    max = float("-inf")
    for i in xrange(0, len(grid)):
      for j in xrange(0, len(grid[i]) - 3):
        productx = grid[i][j] * grid[i][j+1] * grid[i][j+2] * grid[i][j+3]
        producty = grid[j][i] * grid[j+1][i] * grid[j+2][i] * grid[j+3][i]
        if productx > max:
          max = productx
        elif producty > max:
          max = producty
  
    for i in xrange(0, len(grid) - 3):
      productd = grid[i][i] * grid[i+1][i+1] * grid[i+2][i+2] * grid[i+3][i+3]
      if productd > max: max = productd
    print max
  
  if __name__ == '__main__':
    L = []
  L.append("08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08")
  L.append("49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00")
  L.append("81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65")
  L.append("52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91")
  L.append("22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80")
  L.append("24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50")
  L.append("32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70")
  L.append("67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21")
  L.append("24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72")
  L.append("21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95")
  L.append("78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92")
  L.append("16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57")
  L.append("86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58")
  L.append("19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40")
  L.append("04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66")
  L.append("88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69")
  L.append("04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36")
  L.append("20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16")
  L.append("20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54")
  L.append("01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48")
  M = [i.split() for i in L]
  M = [[int(j) for j in i] for i in M]
  largest_grid_product(M)
  
new_contents: def largest_grid_product(grid):
    max = float("-inf")
    for i in xrange(0, len(grid)):
      for j in xrange(0, len(grid[i]) - 3):
        productx = grid[i][j] * grid[i][j+1] * grid[i][j+2] * grid[i][j+3]
        producty = grid[j][i] * grid[j+1][i] * grid[j+2][i] * grid[j+3][i]
        if productx > max:
          max = productx
        elif producty > max:
          max = producty
  
    for i in xrange(0, len(grid) - 3):
      productd = grid[i][i] * grid[i+1][i+1] * grid[i+2][i+2] * grid[i+3][i+3]
      if productd > max: max = productd
    print max
  
  if __name__ == '__main__':
    L = []
    L.append("08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08")
    L.append("49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00")
    L.append("81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65")
    L.append("52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91")
    L.append("22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80")
    L.append("24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50")
    L.append("32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70")
    L.append("67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21")
    L.append("24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72")
    L.append("21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95")
    L.append("78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92")
    L.append("16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57")
    L.append("86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58")
    L.append("19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40")
    L.append("04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66")
    L.append("88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69")
    L.append("04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36")
    L.append("20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16")
    L.append("20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54")
    L.append("01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48")
    M = [i.split() for i in L]
    M = [[int(j) for j in i] for i in M]
    largest_grid_product(M)
  
subject: fix whitespace