#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n,i,j=0,m,k;
	cin>>n;
	cin>>k;
	int h[10000];
	for(i=0;i<n;i++){
		cin>>h[i];
	} 
	for(i=1;i<=n-1;i++){
		for(j=1;j<=n-i;j++){
			if(h[j-1]<h[j]){
				swap(h[j-1],h[j]);
			}
		}
	}
	k--;
	m=h[k]-h[n-1-k];
	if((m!=2&&m%2==0)||(m!=3&&m%3==0)||(m!=5&&m%5==0)||(m!=7&&m%7==0)){
		cout<<"NO"<<endl;
	}else{
		cout<<"YES"<<endl;
	}
	cout<<m;
	return 0;
}
/**************************************************************
	Problem: 1242
	User: zzz
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/