#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

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