#include <iostream>
#include <list>
#include <vector>
#include <string>
#include <stdio.h>
#include <stdint.h>
#include <iomanip>
using namespace std;

using uint = unsigned int;
using ll = long long;

#define CIN( LL , A ) LL A; cin >> A 
#define GETLINE( A ) string A; getline( cin , A ) 
#define FOR_ITR( ARRAY , ITR , END ) for( auto ITR = ARRAY .begin() , END = ARRAY .end() ; ITR != END ; ITR ++ ) 

int main()
{

  CIN( ll , n );
  CIN( ll , a );
  a *= n;
  ll x;
  for( ll i = 0 ; i < n ; i++ ){
    cin >> x;
    a -= x;
  }
  const string answer = a == 0 ? "YES" : "NO";
  cout << answer << endl;
  return 0;

}