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

#define ll long long
#define vvi vector<vector<int>>
#define vec vector
#define pq priority_queue
#define all(v) (v).begin(), (v).end()
#define rep(i, n, m) for (int (i) = (n); (i) < (m); ++(i))
#define debug(x) cerr << #x << ": " << x << endl;
#define debug2(x, y) cerr<<"("<<#x<<", "<<#y<<") = "<<"("<<x<<", "<<y<<")"<<endl;
#define debugB(x, y) cerr<<#x<<": "<<bitset<y>(x) << endl;
#define line() cerr << "---------------" << endl;

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

int main() {
   int n;
   cin >> n;
   n--;
   int digit = 0, zero = 0;
   while (n > 0) {
      if ((n&1)==0) {
         zero++;
      }
      n = (n>>1);
      digit++;
   }
   cout << digit + zero << endl;

   return 0;
}