def basement_pos(plan: str):
    f = 0
    for i,e in enumerate(plan):
        f = f+1 if e == '(' else f-1
        if f == -1:
            return i+1

def test():
    assert basement_pos(")") == 1
    assert basement_pos("()())") == 5

def solve():
    with open("in2") as puzzle:
        r = puzzle.read()
    return basement_pos(r)

if __name__ == "__main__":
    print(f"Basement position: {solve()}")