#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int (i)=(0);(i)<(int)(n);++(i))
using ll = long long;
using P = pair<int, int>;
using namespace std;

int main() {
    int N;
    cin >> N;

    int b = 0, num = 1;
    while (num < N) {
        num *= 2;
        b++;
    }

    cout << b << endl;

    return 0;
}