#include <iostream>
 
using namespace std;
 
int main(){
  int n;
  cin>>n;
  if(n==1){
    cout << 0 << endl;
  }
  int ans = 1;
  for(int i = 2;;i*=2){
    if(n<=i){
      cout << ans << endl;
      return 0;
    }
    ans++;
  }
  return 0;
}