#!/bin/python

import sys

flag=0
flag1=0
n = int(raw_input().strip())
for a0 in xrange(n):
    x,y = raw_input().strip().split(' ')
    x,y = [int(x),int(y)]
    flag=abs(x)+flag
    flag1=abs(y)+flag1
    if(x>0 and y>0):
        flag=1
if(flag==1):
    print "NO"
else:
    print "YES"
    
#if flag==0 and flag1>0:
#    print "YES"
#elif flag>0 and flag1==0:
#    print "YES"
#elif flag==0 and flag1==0:
#    print "YES"
#else:
 #   print "NO"