from itertools import accumulate
n=int(input())
p=[0]*(5*(10**5)+100)
for _ in range(n):
    x,r=map(int,input().split())
    x+=(10**5)*2+100
    p[x-r]+=1
    p[x+r+1]-=1
q=list(accumulate(p))
print(max(q))