#include "bits/stdc++.h"
using namespace std;

typedef long long Int;
#define REP(i,n) for(int (i)=0;(i)<(int)(n);++(i))

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