# input = """.......S.......
# ...............
# .......^.......
# ...............
# ......^.^......
# ...............
# .....^.^.^.....
# ...............
# ....^.^...^....
# ...............
# ...^.^...^.^...
# ...............
# ..^...^.....^..
# ...............
# .^.^.^.^.^...^.
# ..............."""

with open("input.txt", "r") as file:
    input = file.read()


def count_timelines(grid: str) -> int:
    lines = grid.splitlines()
    H = len(lines)
    W = len(lines[0])

    # стартовая колонка S
    s_col = lines[0].index("S")

    counts = [0] * W
    counts[s_col] = 1  # одна частица -> один таймлайн в старте

    for i in range(1, H):
        new = [0] * W
        row = lines[i]
        for j, cell in enumerate(row):
            k = counts[j]
            if k == 0:
                continue

            if cell == "^":
                # splitter: поток не проходит вниз, а расходится влево/вправо
                if j - 1 >= 0:
                    new[j - 1] += k
                if j + 1 < W:
                    new[j + 1] += k
            else:
                # пусто: идем прямо вниз
                new[j] += k

        counts = new

    return sum(counts)

print(count_timelines(input))