t = """
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 find_greatest_path_sum_in_triangle_string(ts):
    from functools import reduce
    xss = [list(map(int, xs.split())) for xs in ts.split("\n") if xs]
    xss.reverse()

    def r(xs, ys):
        return [max([xs[i] + ys[i], xs[i + 1] + ys[i]])
                for i in range(len(ys))]
    return reduce(r, xss[1:], xss[0])[0]


def euler_018():
    return find_greatest_path_sum_in_triangle_string(t)


if __name__ == "__main__":
    assert(euler_018() == 1074)
    print("e018.py: {}".format(euler_018()))