#include <iostream>
#include <iomanip>
#include <cmath>
 
using namespace std;
 bool sushu(int n){
    int i,s=0,j;
    bool f=true;
        for(j=2;j<=sqrt(n);j++){
            if(n%j==0){
                f=false;
            }
        }
        if(n==1){
           f=false;
        }
    return f;
}
int main(){
    int n,k,j,t,i,a[1000],s[1000]{0};
    bool f=false;
    cin>>n>>k;
    for(i=0;i<n;i++){
        cin>>a[i];
    }
    for(i=0;i<n;i++){
     for(j=0;j<n-i-1;j++){
        if(a[j]<a[j+1]){
            t=a[j];
            a[j]=a[j+1];
            a[j+1]=t;
         }
     }
}
    if(k>n/2){
    	k=n-k;
	}
    if(sushu(a[k-1]-a[n-k])==true){
    	cout<<"YES"<<endl;
	}
	else{
		cout<<"NO"<<endl;
	}
    cout<<a[k-1]-a[n-k]<<endl;
} 
/**************************************************************
	Problem: 1242
	User: admin
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/