from pathlib import Path

FILE = "input.txt"

def main():
    raw_lines = Path(FILE).read_text().splitlines()
    beams = {raw_lines[0].index('S')}
    splits = 0
    for line in raw_lines[1:]:
        for i, c in enumerate(line):
            if c == '^':
                if i in beams:
                    splits += 1
                    beams.remove(i)
                    beams.add(i-1)
                    beams.add(i+1)
    return splits


if __name__ == "__main__":
    print(main())