n = int(input())
cnt = [0 for _ in range(4 * 10 ** 5 + 1)]
C = 2 * 10 ** 5
for _ in range(n):
    x, r = map(int, input().split())
    cnt[x - r + C] += 1
    cnt[x + r + C] -= 1

ans = 0
total = 0
for num in cnt:
    total += num
    ans = max(ans, total)
print(ans)