import sys

n = int(eval(input()))

info = [0] * n

for i in range(n):

    x, l = list(map(int, input().split()))

    info[i] = [x+l, x, l]



info.sort()

ans = 1

right = info[0][1] + info[0][2]

for i in range(1, n):

    if right <= info[i][1] - info[i][2]:

        ans += 1

        right = info[i][1] + info[i][2]

print(ans)
import sys

input = sys.stdin.readline

n = int(eval(input()))

info = [0] * n

for i in range(n):

    x, l = list(map(int, input().split()))

    info[i] = [x+l, x, l]



info.sort()

ans = 1

right = info[0][1] + info[0][2]

for i in range(1, n):

    if right <= info[i][1] - info[i][2]:

        ans += 1

        right = info[i][1] + info[i][2]

print(ans)
import sys

n = int(eval(input()))
info = [0] * n
for i in range(n):
    x, l = list(map(int, input().split()))
    info[i] = [x + l, x, l]
info.sort()
ans = 1
right = info[0][1] + info[0][2]
for i in range(1, n):
    if right <= info[i][1] - info[i][2]:
        ans += 1
        right = info[i][1] + info[i][2]
print(ans)

import sys

input = sys.stdin.readline
n = int(eval(input()))
info = [0] * n
for i in range(n):
    x, l = list(map(int, input().split()))
    info[i] = [x + l, x, l]
info.sort()
ans = 1
right = info[0][1] + info[0][2]
for i in range(1, n):
    if right <= info[i][1] - info[i][2]:
        ans += 1
        right = info[i][1] + info[i][2]
print(ans)

+input = sys.stdin.readline