#Maximum path sum I
#Problem 18
#Published on Friday, 31st May 2002, 06:00 pm; Solved by 63589
#
#By starting at the top of the triangle below and moving to adjacent numbers on
#the row below, the maximum total from top to bottom is 23.
#
#3
#7 4
#2 4 6
#8 5 9 3
#
#That is, 3 + 7 + 4 + 9 = 23.
#
#Find the maximum total from top to bottom of the triangle below:
#
#75
#95 64
#17 47 82
#18 35 87 10
#20 04 82 47 65
#19 01 23 75 03 34
#88 02 77 73 07 63 67
#99 65 04 28 06 16 70 92
#41 41 26 56 83 40 80 70 33
#41 48 72 33 47 32 37 16 94 29
#53 71 44 65 25 43 91 52 97 51 14
#70 11 33 28 77 73 17 78 39 68 17 57
#91 71 52 38 17 14 91 43 58 50 27 29 48
#63 66 04 68 89 53 67 30 73 16 69 87 40 31
#04 62 98 27 23 09 70 98 73 93 38 53 60 04 23
#
#NOTE: As there are only 16384 routes, it is possible to solve this problem by
#trying every route. However, Problem 67, is the same challenge with a triangle
#containing one-hundred rows; it cannot be solved by brute force, and requires
#a clever method! ;o)
#

a = [
[ 75 ],
[ 95, 64 ],
[ 17, 47, 82 ],
[ 18, 35, 87, 10 ],
[ 20,  4, 82, 47, 65 ],
[ 19,  1, 23, 75,  3, 34 ],
[ 88,  2, 77, 73,  7, 63, 67 ],
[ 99, 65,  4, 28,  6, 16, 70, 92 ],
[ 41, 41, 26, 56, 83, 40, 80, 70, 33 ],
[ 41, 48, 72, 33, 47, 32, 37, 16, 94, 29 ],
[ 53, 71, 44, 65, 25, 43, 91, 52, 97, 51, 14 ],
[ 70, 11, 33, 28, 77, 73, 17, 78, 39, 68, 17, 57 ],
[ 91, 71, 52, 38, 17, 14, 91, 43, 58, 50, 27, 29, 48 ],
[ 63, 66,  4, 68, 89, 53, 67, 30, 73, 16, 69, 87, 40, 31 ],
[  4, 62, 98, 27, 23,  9, 70, 98, 73, 93, 38, 53, 60,  4, 23 ] ]

for i in reversed(range(0,len(a)-1)):
    for j in range(0,len(a[i])):
        a[i][j] += max(a[i+1][j],a[i+1][j+1])


print(a[0][0])