这题没人用二分吗

#include<bits/stdc++.h>
using namespace std;
#define ll unsigned long long

ll n;

int main() {
	cin >> n;
	if (1 <= n && n <= 7) {
		cout << 1;
	} else if (8 <= n && n <= 26) cout << 2;
	else if (27 <= n && n <= 63) cout << 3;
	else if (64 <= n && n <= 124) cout << 4;
	else {
		//二分的部分就不展示啦啦
	}
}