N = int(eval(input()))

num_list = [[int(item) for item in input().split()] for _ in range(N)]

num_list2 = []

for x, l in num_list:

    num_list2.append([x-l, x+l])



num_list2.sort(key=lambda x: x[1]) 

# print(num_list2)



temp_max = num_list2[0][1]

cnt = 1



for l, h in num_list2:

    if l >= temp_max:

        cnt += 1

        temp_max = h



print(cnt)

def resolve():

    '''

    code here

    '''

    N = int(eval(input()))

    robots = [[int(item) for item in input().split()] for _ in range(N)]





    arm_body_arm = []



    for body, arm in robots:

        arm_body_arm.append([body - arm, body + arm])

    

    arm_body_arm = sorted(arm_body_arm, key=lambda x:x[1])



    res = 1

    prev = arm_body_arm[0][1]

    for start, end in arm_body_arm:

        if prev <= start:

            res += 1

            prev = end



    print(res)



if __name__ == "__main__":

    resolve()

N = int(eval(input()))
num_list = [[int(item) for item in input().split()] for _ in range(N)]
num_list2 = []
for x, l in num_list:
    num_list2.append([x - l, x + l])
num_list2.sort(key=lambda x: x[1])
# print(num_list2)
temp_max = num_list2[0][1]
cnt = 1
for l, h in num_list2:
    if l >= temp_max:
        cnt += 1
        temp_max = h
print(cnt)

def resolve():
    """
    code here
    """
    N = int(eval(input()))
    robots = [[int(item) for item in input().split()] for _ in range(N)]
    arm_body_arm = []
    for body, arm in robots:
        arm_body_arm.append([body - arm, body + arm])
    arm_body_arm = sorted(arm_body_arm, key=lambda x: x[1])
    res = 1
    prev = arm_body_arm[0][1]
    for start, end in arm_body_arm:
        if prev <= start:
            res += 1
            prev = end
    print(res)


if __name__ == "__main__":
    resolve()

-N = int(eval(input())) -num_list = [[int(item) for item in input().split()] for _ in range(N)] -num_list2 = [] -for x, l in num_list: -    num_list2.append([x - l, x + l]) -num_list2.sort(key=lambda x: x[1]) -# print(num_list2) -temp_max = num_list2[0][1] -cnt = 1 -for l, h in num_list2: -    if l >= temp_max: -        cnt += 1 -        temp_max = h -print(cnt) +def resolve(): +    """ +    code here +    """ +    N = int(eval(input())) +    robots = [[int(item) for item in input().split()] for _ in range(N)] +    arm_body_arm = [] +    for body, arm in robots: +        arm_body_arm.append([body - arm, body + arm]) +    arm_body_arm = sorted(arm_body_arm, key=lambda x: x[1]) +    res = 1 +    prev = arm_body_arm[0][1] +    for start, end in arm_body_arm: +        if prev <= start: +            res += 1 +            prev = end +    print(res) + + +if __name__ == "__main__": +    resolve()