#!/usr/bin/python

tri ="""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"""

def preprocess():
    global tri
    tri = tri.split('\n')
    t = []
    for arr in tri:
        t.append(map(int, arr.split(' ')))
    tri = t

def calc(row, col):
    try:
        tri[row+1][col]
        tri[row+1][col+1]
    except IndexError:
        return tri[row][col]
    return tri[row][col] + max([calc(row+1,col), calc(row+1,col+1)])

def solve():
    preprocess()

    print calc(0, 0)

def main():
    import time
    print "Start"
    s = time.time()
    solve()
    e = time.time()
    print "Problem solved in", e-s, "second"

if __name__ == '__main__':
    main()
