#include <bits/stdc++.h>
using namespace std;

signed main(){
    int n,a;cin>>n>>a;
    double b=0;
    for(int i=0;i<n;i++){
        int k;cin>>k;b+=k;
    }
    b/=(double)n;
    if(abs(a-b)<0.1)cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
}