import sys,random,bisect
from collections import deque,defaultdict
from heapq import heapify,heappop,heappush
from itertools import permutations
from math import gcd
from fractions import Fraction

input = lambda :sys.stdin.readline().rstrip()
mi = lambda :map(int,input().split())
li = lambda :list(mi())

N = int(input())
for _ in range(N):
    v,w = mi()
    if w==1:
        exit(print("Yes"))
print("No")