#include <bits/stdc++.h>

#define mp make_pair
#define mt make_tuple
#define pb push_back
#define rep(i, n) for (int i = 0; i < (n); i++)

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<long, long> pll;

const int INF = 1 << 29;
const double EPS = 1e-9;
const int MOD = 100000007;
int N;

int main(){
  int pos = 1;
  cin >> N;
  int cnt = 0;
  while (pos < N){
    pos *= 2;
    cnt++;
  }
  cout << cnt << endl;
}