#include<bits/stdc++.h> using namespace std; using ll = long long; template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; } template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; } #define FOR(i,a,b) for(ll i=(a);i<(b);++i) #define ALL(v) (v).begin(), (v).end() #define p(s) cout<<(s)<<endl #define p2(s, t) cout << (s) << " " << (t) << endl #define br() p("") #define pn(s) cout << (#s) << " " << (s) << endl #define p_yes() p("YES") #define p_no() p("NO") int main(){ cin.tie(0); ios::sync_with_stdio(false); // input ll n, mean; cin >> n >> mean; ll sum = 0; FOR(i, 0, n){ ll a; cin >> a; sum += a; } if(sum == n*mean){ p_yes(); }else{ p_no(); } return 0; }