#include #include #include #include #include using namespace std; #define FOR(i,a,b) for (int i = (a); i < (b); i++) #define REP(i,n) FOR(i,0,n) typedef long long ll; int main(){ int n, a; cin >> n >> a; int sum = 0; REP(i,n){ int num; cin >> num; sum += num; } if ((double)sum/(double)n == (double)a) cout << "YES" << endl; else cout << "NO" << endl; return 0; }