题解

#include <iostream>
using namespace std;

bool judge(long long n) {
    if (n==0) return 0;
    while (n) {
        if (n==1) return 1;
        if (n%2==1) return 0;
        n/=2;
    }
    return 1;
}

int main() {
    long long n;
    cin >> n;
    cout << (judge(n)?"YES":"NO");
    return 0;
}