#!/usr/bin/python3

slope = []
with open("input") as fh:
    for ln in fh:
        row = []
        for c in ln:
            if c == "#":
                row.append(True)
            elif c == ".":
                row.append(False)
            elif c == "\n":
                pass
            else:
                raise RuntimeError("impossible")
        slope.append(row)
def trees(slope, right, down):
    xmod = len(slope[0])
    x = 0
    y = 0
    trees = 0
    while y < len(slope):
        trees += slope[y][x % xmod]
        x += right
        y += down
    print(right, down, trees)
    return trees

t1 = (trees(slope, 1, 1))
t2 = (trees(slope, 3, 1))
t3 = (trees(slope, 5, 1))
t4 = (trees(slope, 7, 1))
t5 = (trees(slope, 1, 2))
print(t1 * t2 * t3 * t4 * t5)