#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> P;
typedef pair<int,pair<int,int>> PP;
typedef long long ll;

const double EPS = 1e-8;
const int INF = 1e9;
const int MOD = 1e9+7;

int dy[] = {0,1,0,-1};
int dx[] = {1,0,-1,0};

int main(void) {
	int n;
	cin >> n;

	int a = 1;
	int cnt = 0;
	while(a < n){
		a *= 2;
		cnt++;
	}
	cout << cnt << endl;

	return 0;
}