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


import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;

public class Codechef
{
	public static void main (String[] args) throws java.lang.Exception
	{
	    Scanner sc = new Scanner(System.in);
int t=1;
while(t-->0)
{
	
	int i = sc.nextInt();
	int j = sc.nextInt();
	
	result(i, j);
}

	}
	
public static void result(int i, int j)
{
    int prime[] = new int[j+1];
    Arrays.fill(prime,1);
    prime[0]=0;
    prime[1]=0;
   

    for(int k=2;k<=j;k++)
    {
        if(prime[k]==1)
     {   for(int l=2;l<=j/k;l++)
        {
            prime[l*k]=0;
        }
        
    }
   
    }
    
 //System.out.println(Arrays.toString(prime));
    
    for(int k=(int)i+1;k<j;k++)
    {
        if(prime[k]==1)
        {
            System.out.println("NO");
            return;
        }
    }
    if(prime[j]==1 &&prime[i]==1)
    System.out.println("YES");
    else
    System.out.println("NO");
    
}


}
