#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < n; i++)
using namespace std;

int n;

int main(){
	cin >> n;
	int x = 1;
	int cnt = 0;
	for(;;){
		if(n <= x) break;
		x *= 2;
		cnt++;
	}
	cout << cnt << endl;
}