def main():
    inp1 = int(input())

    count = 0
    num = 1
    loop_flg = True
    while loop_flg:
        if num == 1:
            num += 1
        else:
            num = num * 2
        count += 1
        if num >= inp1:
            loop_flg = False
        else:
            break
    print(count)


if __name__ == '__main__':
    main()