""" Project Euler problem #18. """


def problem():
    """ Solve the problem.

    Find the maximum total from top to bottom of the triangle below.

    Answer:

    """
    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 = [
        map(int, l.strip().split()) for l in triangle.split('\n') if l.strip()]

    gen = iter(reversed(triangle))
    sums = next(gen)

    def grouper(nodes):
        for n in range(len(nodes) - 1):
            yield nodes[n], nodes[n+1]

    for nodes in gen:
        sums = [s + max(nn) for s, nn in zip(nodes, grouper(sums))]

    return sums[0]


if __name__ == '__main__':
    print problem()

Solve 18.