#include <bits/stdc++.h>
using namespace std;

int main() {
	long long a, cnt = 0;
	cin >> a;
	for (int i = 1; i <= a; i *= 2) {
		cnt++;
	}
	cout << cnt;
	return 0;
}
点点赞

#include using namespace std;

int main() { long long a, cnt = 0; cin >> a; for (int i = 1; i <= a; i *=2) { cnt++; } cout << cnt; return 0; }//点点赞

#include using namespace std;

int main() { long long a, cnt = 0; cin >> a; for (int i = 1; i <= a; i *= 2) { cnt++; } cout << cnt; return 0; }

#include using namespace std;

int main() { long long a, cnt = 0; cin >> a; for (int i = 1; i <= a; i *= 2) { cnt++; } cout << cnt; return 0; }