import math
n = int(input())
print("YES" if all(n%i!=0 for i in range(2,int(math.sqrt(n))+1)) and n>1 else "NO")

import math

def check(x):
    for i in range(2, int(math.sqrt(x)) + 1):
        if x % i == 0:
            return False
    return x > 1

n = int(input())
print("YES" if check(n) else "NO")

#include <bits/stdc++.h>
using namespace std;
bool check (long long x)
{
    for(long long i=2;i<=sqrt(x);++i)
    if (x%i==0) return false;
    return x>1;
}
long long n;
int main()
{
    cin>>n;
    cout<<(check(n)?"YES":"NO");
    return 0;
}