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

int main(){
    long long n;
    cin >> n;
    bool flag = true;
    if (n < 2) flag = false;
    for (long long i = 2; i * i <= n; i++)
    {
        if (n % i == 0)
        {
            flag = false;
            break;
        }
    }
    if (flag)
        cout << "Yes";
    else
        cout << "No";
    return 0;
}