#include<bits/stdc++.h>
using namespace std;
long long n;
int main() {
	cin >> n;
    int a;
    if(n%2==0){
    	a=0;
    	
	}else{
		a=1;
		n=n-1;
	}

	while(n>1){
		n=n/2;
		a++;
	}
	cout << a << endl;
	return 0;
}