A prime number is a number which has exactly two distinct divisors: one and itself. For example, numbers 2, 7, 3 are prime, and 1, 6, 4 are not.

The next prime number after x is the smallest prime number greater than x. For example, the next prime number after 2 is 3, and the next prime number after 3 is 5. Note that there is exactly one next prime number after each number. So 5 is not the next prime number for 2.

One cold April morning Panoramix predicted that soon Kakofonix will break free from his straitjacket, and this will be a black day for the residents of the Gallic countryside.

Panoramix's prophecy tells that if some day Asterix and Obelix beat exactly x Roman soldiers, where x is a prime number, and next day they beat exactly y Roman soldiers, where y is the next prime number after x, then it's time to wait for Armageddon, for nothing can shut Kakofonix up while he sings his infernal song.

Yesterday the Gauls beat n Roman soldiers and it turned out that the number n was prime! Today their victims were a troop of m Romans (m > n). Determine whether the Gauls should wait for the black day after today's victory of Asterix and Obelix?

Input

The first and only input line contains two positive integers — n and m (2 ≤ n < m ≤ 50). It is guaranteed that n is prime.

Pretests contain all the cases with restrictions 2 ≤ n < m ≤ 4.

Output

Print YES, if m is the next prime number after n, or NO otherwise.

Examples

Input

3 5


Output

YES

Input

7 11


Output

YES

Input

7 9


Output

NO
/*  Author : Alpha_The_Coder
    Created On 25/12/2020                           */
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        FastScanner sc=new FastScanner();
        int n=sc.nextInt();
        int m=sc.nextInt();

        boolean ok=isPrime(m);
        if (!ok)
        {
            System.out.println("NO");
            System.exit(0);
        }
        for (int i = n+1; i <=m ; i++) {
            if (isPrime(i) && i!=m)
            {
                ok=false;
                break;
            }
        }
        if (ok) System.out.println("YES");
        else System.out.println("NO");
    }
    public static boolean isPrime(int n)
    {
        for (int i = 2; i <=(int)Math.sqrt(n) ; i++) {
            if (n%i==0)
                return false;
        }
        return true;
    }
    //  RBGGRGBRRGBR           GR
    static class FastScanner {
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st=new StringTokenizer("");
        String next() {
            while (!st.hasMoreTokens())
                try {
                    st=new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }
        int[] readArray(int n) {
            int[] a=new int[n];
            for (int i=0; i<n; i++) a[i]=nextInt();
            return a;
        }
        String[] readStringArray(int n) {
            String[] s=new String[n];
            for (int i=0; i<n; i++) s[i]=next();
            return s;
        }
        long nextLong() {
            return Long.parseLong(next());
        }
    }
}
// This code is solely contributed by Subhojeet Sahoo aka Alpha_The_Coder