__author__ = 'Rushil'

triangle = '''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'''

triangle = [list(map(int , i.split(' '))) for i in triangle.split('\n')]

def all_paths(r , c):
    current = triangle[r][c]
    if r < len(triangle) - 1:
        paths_below = all_paths(r+1 , c) + all_paths(r+1 , c+1)
        return [[current] + path for path in paths_below]
    else:
        return [[current]]

all_sums = []

for i in all_paths(0 , 0):
    all_sums.append(sum(i))

print(max(all_sums))