n = int(input())
a = [0] * (4 * 10 ** 5 + 1)
for _ 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))