#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using Graph = vector<vector<int>>;
int main() {
  long long N; cin >>N;
  long long x = 1;
  long long count = 0;
  map<int,int> dic;
  dic[1] = 0;
  for(int i = 0; i < 32; i++) {
    x *= 2;
    dic[x] = i + 1;
    
  }
 
  if(dic[N] > 0) {
    cout << dic[N] << endl;
    return 0;
    
  }
  if(N == 1) {
    cout << 0 << endl;
    return 0;
  }
  while(true) {
    N /= 2;
    count++;
    if(N == 0) {
      break;
    }
   
  }
  cout << count << endl;
}