n=int(input())
S=[0]*(10**6)


for i in range(n):
    x,r=map(int,input().split())
    x*=2

    x+=500000
    S[x-2*r+1]+=1
    S[x+2*r]-=1

for i in range(10**6):
    S[i]+=S[i-1]

print(max(S))