import numpy as np


def main():
    N = int(input())
    grids = np.array([0 for _ in range(400001)])
    for _ in range(N):
        center, radius = map(int, input().split())
        grids[200000+center-radius:200000+center+radius] += 1

    print(max(grids))


if __name__ == "__main__":
    main()