#include<iostream>
#include<string>
#include<math.h>
using namespace std;

int main() {
	int long n,sum,psum;
	cin >> n;
	sum = 1;
	psum = 0;
		for (int i = 0; i < 100000; i++) {
			psum = pow(2, i);
			if (psum > n) { 
				cout << i ;
				break;
			}
			else if (psum == n) {
				cout << i;
				break;
			}
		}
	
}