#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <map>
#include <queue>
typedef long long ll;
using namespace std;
#define rep(i, n) for (int i = 0; i <= (int)(n); i++)
#define mod 1000000007

int main(){
	int N;
	cin >> N;
	int ans = 0;
	int B = 1;
	while(B < N){
		B *= 2;
		ans++;
	}
	cout << ans << endl;
}