import sys
import math as mas

n=int(input())
ma=0
for i in range(n):
	a,b=map(int,input().split())
	ma=max(ma,a-30000*b)
if ma>=500000:print("YES")
else:print("NO")

#for i in sys.stdin:
#	a,b=map(int,i.split())
#	print(gcd(a,b),lcm(a,b))