#include <bits/stdc++.h>
#define rep(i, n) for(long long i = 0; i < n; i++)
#define ALL(v) (v).begin(), (v).end()
#define rALL(v) (v).rbegin(), (v).rend()
using namespace std;

using lint = long long;

int main() {
    int n;
    cin >> n;
    int ans = 0;
    while ((1 << ans) < n) {
        ans++;
    }
    cout << ans << endl;
}