#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;
}
/**************************************************************
	Problem: 1242
	User: yangjunwen
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/