#include <iostream>
#include <algorithm>
#include <string>
using namespace std;

int main() {
	long long x, cnt=0, ans, remain;
	cin >> x;
	while(x > 2){
		x /= 2;
		 remain = x % 2;
		cnt++;
	}
	if(remain == 0){
		ans = cnt;
	}else{
		ans = cnt + 1;
	}
	cout << ans << endl;
	return 0;
}