n = int(input())
events = []
for _ in range(n):
    x, r = map(int, input().split())
    start = x - r
    end = x + r
    events.append((start, 1))
    events.append((end, -1))

events.sort()
current = 0
max_count = 0
for x, delta in events:
    current += delta
    if current > max_count:
        max_count = current

print(max_count)