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.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Scanner;
import java.util.function.Function;
import java.util.stream.Collectors;
public class _p000080A {
    static public void main(final String[] args) throws IOException {
        p000080A._main(args);
    }
//begin p000080A.java
static private class p000080A extends Solver{public p000080A(){nameIn="p000080A.in"
;singleTest=true;}int n;int m;@Override protected void solve(){int[]herato=new int
[m+1];int i=2;boolean res=false;while(i<herato.length){int pos=i;while(true){pos
+=i;if(pos>=herato.length){break;}herato[pos]=1;}i++;while(i<herato.length&&herato
[i]==1){i++;}}if(herato[m]==0){res=true;for(int j=n+1;j<m;j++){if(herato[j]==0){
res=false;break;}}}pw.println(res?"YES":"NO");}@Override public void readInput()
throws IOException{n=sc.nextInt();m=sc.nextInt();if(sc.hasNextLine()){sc.nextLine
();}}static public void _main(String[]args)throws IOException{new p000080A().run
();}}
//end p000080A.java
//begin net/leksi/contest/Solver.java
static private abstract class Solver{protected String nameIn=null;protected String
nameOut=null;protected boolean singleTest=false;protected boolean preprocessDebug
=false;protected boolean doNotPreprocess=false;protected Scanner sc=null;protected
PrintWriter pw=null;private void process()throws IOException{if(!singleTest){int
t=lineToIntArray()[0];while(t-->0){readInput();solve();}}else{readInput();solve(
);}}abstract protected void readInput()throws IOException;abstract protected void
solve()throws IOException;protected int[]lineToIntArray()throws IOException{return
Arrays.stream(sc.nextLine().trim().split("\\s+")).mapToInt(Integer::valueOf).toArray
();}protected long[]lineToLongArray()throws IOException{return Arrays.stream(sc.nextLine
().trim().split("\\s+")).mapToLong(Long::valueOf).toArray();}protected String joinToString
(final int[]a){return Arrays.stream(a).mapToObj(Integer::toString).collect(Collectors
.joining(" "));}protected String joinToString(final long[]a){return Arrays.stream
(a).mapToObj(Long::toString).collect(Collectors.joining(" "));}protected<T>String
joinToString(final T[]a){return Arrays.stream(a).map(v->v.toString()).collect(Collectors
.joining(" "));}protected<T>String joinToString(final T[]a,final Function<T,String>
toString){return Arrays.stream(a).map(v->v.toString()).collect(Collectors.joining
(" "));}protected<T>String joinToString(final Collection<T>a){return a.stream().map
(v->v.toString()).collect(Collectors.joining(" "));}protected<T>String joinToString
(final Collection<T>a,final Function<T,String>toString){return a.stream().map(v->
toString.apply(v)).collect(Collectors.joining(" "));}protected List<Long>intArrayToLongList
(final int[]a){return Arrays.stream(a).mapToObj(Long::valueOf).collect(Collectors
.toList());}protected List<Integer>toList(final int[]a){return Arrays.stream(a).mapToObj
(Integer::valueOf).collect(Collectors.toList());}protected List<Long>toList(final
long[]a){return Arrays.stream(a).mapToObj(Long::valueOf).collect(Collectors.toList
());}protected void run()throws IOException{boolean done=false;if(nameIn !=null)
{try{try(FileInputStream fis=new FileInputStream(nameIn);PrintWriter pw0=select_output
();){done=true;sc=new Scanner(fis);pw=pw0;process();}}catch(IOException ex){}}if
(!done){try(PrintWriter pw0=select_output();){sc=new Scanner(System.in);pw=pw0;process
();}}}private PrintWriter select_output()throws FileNotFoundException{if(nameOut
!=null){return new PrintWriter(nameOut);}return new PrintWriter(System.out);}}
//end net/leksi/contest/Solver.java
}
