#include<iostream>
#include<cmath>
using namespace std;

int main()
{
  int M,D;
  cin >> M >> D;
  int X=M*100+D;
  for(int i=2;i<=sqrt(X);i++){
    if(X%i==0){
      cout << "No\n";
      return 0;
    }
  }
  cout << "Yes\n";
  
  return 0;
}