#include<iostream>
using namespace std;

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










	return 0;
}