#include #include using namespace std; using namespace atcoder; #define rep(i,n) for(int i=0;i<(int)(n);i++) template inline bool chmax(T&a,T b){if(a inline bool chmin(T&a,T b){if(a>b){a=b;return 1;}return 0;} using ll = long long; ll n,a,x,sum; int main () { cin.tie(0); ios::sync_with_stdio(false); cin >> n >> a; rep(i,n) cin >> x, sum+=x; cout << (sum==a*n ? "YES" : "NO") << '\n'; }