N = int(input())
geta = 101010 * 2
M = 505050
A = [0] * M
for i in range(N):
    x, r = map(int, input().split())
    A[x - r + 1 + geta] += 1
    A[x + r + geta + 1] -= 1
Ac = [0] * (M + 1)
for i in range(M):
    Ac[i + 1] = Ac[i] + A[i]
print(max(Ac))