import math

def inputs():
    D = int(input())
    return D


def t_input():
    D = 1000
    return D


def test():
    D = t_input()
    cookie = 1
    times = 0
    while(D - cookie > 0):
        cookie *= 2
        times += 1
    print(times)


def solve():
    D = int(input())
    ans = math.ceil(math.log(D, 2))
    print(ans)


if __name__ == '__main__':
    # test()
    solve()