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

int foo(int n){//cout<<n<<endl;int a;cin>>a;
  int i = 1, count = 0;
  while(true){
    /*
    if(i > n){
      //count += foo(n-i/2);
      if((n-i/2)%2==1)count++;
      break;
    } else if(i == n) break;
    else{
      i *= 2;
      count++;
    }*/
    if(i >= n)break;
    i *= 2;
    count++;
    
  }
  return count;
}

int main(){
  int n;
  cin>>n;
  cout<<foo(n)<<endl;
  return 0;
}