#!/usr/bin/env python3


def min_num_of_operations(n):
    b = n.bit_length()
    left_pow = 2 ** (b - 1)
    right_pow = 2 ** b
    if left_pow == n:
        return b - 1
    else:
        assert left_pow < n < right_pow
        return b + right_pow - n


def main():
    print(min_num_of_operations(int(input())))


if __name__ == '__main__':
    main()