#include <bits/stdc++.h>
using namespace std;

int main(){
    string s;
    unsigned long long n;
    cin >> n;
    if ((n & (n-1)) == 0) {
        cout <<  int(log2(n)) << endl ;
    }else{
        cout << int(floor(log2(n)) +1) << endl ;
    }
    return 0;
}