#include using namespace std; typedef long long ll; typedef pair p_ll; template void debug(T itr1, T itr2) { auto now = itr1; while(now=0; i--) const ll MOD = pow(10,9)+7; const ll LLINF = pow(2,61)-1; const int INF = pow(2,30)-1; vector fac; void c_fac(int x=pow(10,6)+10) { fac.resize(x,true); rep(i,x) fac[i] = i ? (fac[i-1]*i)%MOD : 1; } ll inv(ll a, ll m=MOD) { ll b = m, x = 1, y = 0; while (b!=0) { int d = a/b; a -= b*d; swap(a,b); x -= y*d; swap(x,y); } return (x+m)%m; } ll nck(ll n, ll k) { return fac[n]*inv(fac[k]*fac[n-k]%MOD)%MOD; } ll gcd(ll a, ll b) { if (a> N; int ok[10][10] = {}; ok[2][8] = 1; ok[3][9] = 2; ok[7][9] = 3; rep(i,N) { ll x1, y1, x2, y2; cin >> x1 >> y1 >> x2 >> y2; ok[x2][y2] = ok[x1][y1]; ok[x1][y1] = 0; } string result = ok[5][8]==1&&ok[4][8]==2&&ok[6][8]==3 ? "YES" : "NO"; cout << result << endl; return 0; }