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

int main() {
    int N;
    cin >> N;
    int sum = 0;
    int tmp = 1;
    int cnt = 1;
    while (true) {
        sum += tmp;
        if(sum >= N) {
            cout << cnt << endl;
            return 0;
        }
        tmp *= 2;
        cnt++;
    }
}