import sys

from operator import itemgetter



input = sys.stdin.readline





def main():

    N = int(eval(input()))

    LR = [None] * N

    for i in range(N):

        X, L = list(map(int, input().split()))

        LR[i] = (X - L, X + L)



    LR.sort(key=itemgetter(0))

    ans = N

    cur_R = LR[0][1]

    for L, R in LR[1:]:

        if L < cur_R:

            ans -= 1

            cur_R = min(cur_R, R)

        else:

            cur_R = R



    print(ans)





if __name__ == "__main__":

    main()

import sys

from operator import itemgetter



input = sys.stdin.readline





def main():

    N = int(eval(input()))

    LR = [None] * N

    for i in range(N):

        X, L = list(map(int, input().split()))

        LR[i] = (X - L, X + L)



    LR.sort(key=itemgetter(0))

    ans = N

    cur_R = LR[0][1]

    for L, R in LR[1:]:

        if L < cur_R:

            ans -= 1

            if R < cur_R:

                cur_R = R

        else:

            cur_R = R



    print(ans)





if __name__ == "__main__":

    main()

import sys
from operator import itemgetter

input = sys.stdin.readline


def main():
    N = int(eval(input()))
    LR = [None] * N
    for i in range(N):
        X, L = list(map(int, input().split()))
        LR[i] = (X - L, X + L)
    LR.sort(key=itemgetter(0))
    ans = N
    cur_R = LR[0][1]
    for L, R in LR[1:]:
        if L < cur_R:
            ans -= 1
            cur_R = min(cur_R, R)
        else:
            cur_R = R
    print(ans)


if __name__ == "__main__":
    main()

import sys
from operator import itemgetter

input = sys.stdin.readline


def main():
    N = int(eval(input()))
    LR = [None] * N
    for i in range(N):
        X, L = list(map(int, input().split()))
        LR[i] = (X - L, X + L)
    LR.sort(key=itemgetter(0))
    ans = N
    cur_R = LR[0][1]
    for L, R in LR[1:]:
        if L < cur_R:
            ans -= 1
            if R < cur_R:
                cur_R = R
        else:
            cur_R = R
    print(ans)


if __name__ == "__main__":
    main()

-            cur_R = min(cur_R, R) +            if R < cur_R: +                cur_R = R