#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long ull;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
    return (ull)rng() % B;
}

int main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	int n; cin >> n; n--;
	int res=0;
	while(n){
		res++;
		if(n%2==0)res++;
		n/=2;
	}	
	printf("%d\n",res);
}