A_Panoramix_s_Prediction.cpp

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


bool isPrime(int n)
{
	if (n <= 1) return false;
	if (n <= 3) return true;

	
	if (n%2 == 0 || n%3 == 0) return false;

	for (int i=5; i*i<=n; i=i+6)
		if (n%i == 0 || n%(i+2) == 0)
		return false;

	return true;
}


int nextPrime(int N)
{

	if (N <= 1)
		return 2;

	int prime = N;
	bool found = false;


	while (!found) {
		prime++;

		if (isPrime(prime))
			found = true;
	}

	return prime;
}


int main()
{
	int m , n;
    cin>>n>>m;

	int np = nextPrime(n);
    if(np == m)
        cout<<"YES"<<endl;
    else
        cout<<"NO"<<endl;

	return 0;
}