#include <iostream>

int main() {
    using namespace std;
    int N;
    cin >> N;
    if (N == 1) {
        cout << 0 << endl;
        return 0;
    }
    int t = 0;
    while(N != 0) {
        N >>= 1;
        ++t;
    }
    cout << t << endl;
    return 0;
}