#include <iostream>
#include <vector>
#include <math.h>
#include <stdio.h>
#include <algorithm>
#include <string>
#include <map>
#include <queue>
#include <memory.h>
#include <bitset>
using namespace std;

typedef pair<int,int> P;

int main() {
  int n;
  cin >> n;
  int a = 1;
  int count = 0;
  while(n > a) {
    a *= 2;
    count++;
  }
  std::cout << count << std::endl;
}