/**
*    author:  boutarou
*    created: 02.08.2020 12:03:04
**/

#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>;

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