#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i=0;i<n;i++)

signed main(){
  int n;
  cin>>n;
  if(n==1){
    cout<<0<<endl;
    return 0;
  }
  int temp=1;
  int cnt=0;
  while(temp*2<=n){
    //cout<<temp<<" "<<cnt<<endl;
    temp*=2;
    cnt++;
  }
  if(temp != n){
    cnt++;
  }
  cout<<cnt<<endl;
  return 0;
}