#yuki1137
n=int(input())
a=[0]*(4*10**5+1)
for i in range(n):
 x,r=map(int,input().split())
 a[x-r+2*10**5]+=1
 a[x+r+2*10**5]-=1
for i in range(len(a)-1):
 a[i+1]+=a[i]
print(max(a))