class DisjointSet(object):
    def __init__(self, n):
        self.parent = list(range(n))
        self.rank = [0] * n
        self.num = n  # number of disjoint sets

    def union(self, x, y):
        self._link(self.find_set(x), self.find_set(y))

    def _link(self, x, y):
        if x == y:
            return
        self.num -= 1
        if self.rank[x] > self.rank[y]:
            self.parent[y] = x
        else:
            self.parent[x] = y
            if self.rank[x] == self.rank[y]:
                self.rank[y] += 1

    def find_set(self, x):
        xp = self.parent[x]
        if xp != x:
            self.parent[x] = self.find_set(xp)
        return self.parent[x]

def read_data():
    N = int(input())
    edges = []
    rcs = set()
    for n in range(N):
        r0, c0, r1, c1 = map(int, input().split())
        (r0, c0), (r1, c1) = sorted([(r0, c0), (r1, c1)])
        edges.append((r0, c0, r1, c1))
        rcs.add((r0, c0))
        rcs.add((r1, c1))
    return N, edges, rcs

def solve(N, edges, rcs):
    np = len(rcs)
    rc2idx = dict()
    for i, (r, c) in enumerate(rcs):
        rc2idx[(r, c)] = i
    idx2e = []
    ds_v = DisjointSet(np)
    for i, (r0, c0, r1, c1) in enumerate(edges):
        p0 = rc2idx[(r0, c0)]
        p1 = rc2idx[(r1, c1)]
        idx2e.append((p0, p1))
        ds_v.union(p0, p1)
    
    ds_v_size = [0] * np
    for p in range(np):
        g = ds_v.find_set(p)
        ds_v_size[g] += 1
    
    e_size = [0] * np
    for i, (p0, p1) in enumerate(idx2e):
        e_size[ds_v.find_set(p0)] += 1
    
    for p in range(np):
        g = ds_v.find_set(p)        
        if g != p:
            continue
        if ds_v_size[g] < e_size[g]:
            return False
    return True

N, edges, rcs = read_data()
if solve(N, edges, rcs):
    print('YES')
else:
    print('NO')