题解

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

int main()
{
    int n;
    cin >> n;
    if (n<=1) cout << "No";
    else if (n==2) cout << "Yes";
    else
    {
    	for (int i=3;i<=sqrt(n)+2;i++)
        {
            if (n%i==0)
            {
                cout << "No";
                return 0;
            }
        }
        cout << "Yes";
    }
    return 0;
}