import sys
from collections import deque

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def paint_col(Adj, cols_v, cols_e, i, col):
    cols_v[i] = col
    nxts = deque([i])

    while nxts:
        u = nxts.popleft()

        for v in Adj[u]:
            if cols_e[min(u, v), max(u, v)] == 0:
                cols_e[min(u, v), max(u, v)] = col
            if cols_v[v] == 0:
                cols_v[v] = col
                nxts.append(v)

    return None

def solve():
    N = int(input())
    p2n = {}
    node = 0
    Adj = []
    cols_v = []
    cols_e = {}

    for i in range(N):
        r0, c0, r1, c1 = map(int, input().split())

        if (r0, c0) not in p2n:
            p2n[r0, c0] = node
            cols_v.append(0)
            node += 1
            Adj.append([])
        if (r1, c1) not in p2n:
            p2n[r1, c1] = node
            cols_v.append(0)
            node += 1
            Adj.append([])

        u, v = p2n[r0, c0], p2n[r1, c1]
        Adj[u].append(v)
        Adj[v].append(u)
        cols_e[min(u, v), max(u, v)] = 0

    # debug(cols_v, locals())
    # debug(cols_e, locals())
    # debug(Adj, locals())

    col = 1

    for i in range(len(cols_v)):
        if cols_v[i] == 0:
            paint_col(Adj, cols_v, cols_e, i, col)
            col += 1

    # debug(cols_v, locals())
    # debug(cols_e, locals())

    for c in range(1, col):
        num_v = sum(i == c for i in cols_v)
        num_e = sum(i == c for i in cols_e.values())

        if num_v + 1 <= num_e:
            print('NO')
            break
    else:
        print('YES')

if __name__ == '__main__':
    solve()