#include<iostream> #include<algorithm> #include<cstdio> #include<cmath> #include<cctype> #include<math.h> #include<string> #include<string.h> #include<stack> #include<queue> #include<vector> #include<utility> #include<set> #include<map> #include<stdlib.h> #include<iomanip> using namespace std; #define ll long long #define ld long double #define EPS 0.0000000001 #define INF 1e9 #define LINF (ll)INF*INF #define MOD 1000000007 #define rep(i,n) for(int i=0;i<(n);i++) #define loop(i,a,n) for(int i=a;i<(n);i++) #define all(in) in.begin(),in.end() #define shosu(x) fixed<<setprecision(x) #define int ll //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! typedef vector<int> vi; typedef vector<string> vs; typedef pair<int,int> pii; typedef vector<pii> vp; int gcd(int a, int b){ if(b==0) return a; return gcd(b,a%b); } int lcm(int a, int b){ return a*b/gcd(a,b); } signed main(void) { int n,a; cin >> n >> a; int sum = 0; rep(i,n){ int t; cin >> t; sum += t; } if(sum == a*n)cout << "YES" << endl; else cout << "NO" << endl; }