#pragma GCC optimize("O3") #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using ll = long long; using P = pair; using T = tuple; template inline T chmax(T &a, const T b) {return a = (a < b) ? b : a;} template inline T chmin(T &a, const T b) {return a = (a > b) ? b : a;} constexpr int MOD = 1e9 + 7; constexpr int inf = 1e9; constexpr long long INF = 1e18; #define all(a) (a).begin(), (a).end() int dx[] = {1, 0, -1, 0}; int dy[] = {0, 1, 0, -1}; int main(){ cin.tie(0); ios::sync_with_stdio(false); int n; cin>>n; vector

abc(3); abc[0] = P(2, 8), abc[1] = P(3, 9), abc[2] = P(7, 9); while(n--){ int px, py, nx, ny; cin>>px>>py>>nx>>ny; for(int i=0; i<3; i++){ if(abc[i] == P(px, py)){ abc[i] = P(nx, ny); } } } cout << ((abc[0] == P(5, 8) && abc[1] == P(4, 8) && abc[2] == P(6, 8)) ? "YES" : "NO") << endl; return 0; }