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

template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

//INSERT ABOVE HERE
signed main(){
  Int n;
  cin>>n;
  Int l=64-__builtin_clzll(n);
  if(__builtin_popcountll(n)==1){
    cout<<l-1<<endl;
    return 0;
  }
  Int x=1LL<<l;
  Int ans=l+__builtin_popcountll(x-n);
  cout<<ans<<endl;
  return 0;
}