#include <bits/stdc++.h>

using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned;

using u128 = unsigned __int128;
using i128 = __int128;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int N;
    std::cin >> N;

    int ans = 0;
    int cur = 1;
    while (cur < N) {
        ans++;
        cur <<= 1;
    }
    std::cout << ans << '\n';

    return 0;
}