#include #define rep(i, x) for(ll i = 0; i < x; i++) #define rep2(i, x) for(ll i = 1; i <= x; i++) #define all(a) (a).begin(),(a).end() using ll = long long; using ld = long double; using namespace std; signed main() { ll a, b, c, d; cin >> a >> b >> c >> d; if (ad) { cout << "YES\n"; } else { cout << "NO\n"; } return 0; }