import time
import random 

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"""

tri = [map(int, x.split(' ')) for x in tri.split("\n")]
maxsum = 0
for x in range(2**len(tri)):
#    time.sleep(0.5)
    pointer = 0
    tempsum = tri[0][0]
    for y in range(1,len(tri)): 
        pointer = pointer + (random.randint(0,1))
        tempsum = tempsum + tri[y][pointer] 
#        print "x: " + str(x) + " y: " + str(y) + " pointer: " + str(pointer)
    maxsum = tempsum if tempsum > maxsum else maxsum

print maxsum
