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.Scanner;

public class Main {
   
void go()
    {
   
    
Scanner s=new Scanner(System.in);
int n,m;
n=s.nextInt();
m=s.nextInt();
String ans="NO";
int k=0,flag=0;
for(int i=n+2;i<=m;)
        {flag=0;for(int j=2;j<=(int)Math.sqrt(i);j++)
                {
         if(i%j==0)
                    {flag=1;
                }
            }if(flag==0)
                {if(i<m){ans="NO"; k=i;break;}k=i;
           }
    i=i+2;
        }
if(k==m)
{ans="YES";

}
if(n==2&&m==3)
{
ans="YES";}
if(n==2&&m!=3)
{
ans="NO";}


System.out.println(ans);
}



    public static void main(String[] args) {
     
Main m=new Main();
m.go();

}
}
