from math import ceil
def update(v: int, tl: int, tr: int, i: int, tree: list, segments: list, dp: list):
if tl == tr:
tree[v] = [tl, tl, dp[tl]]
else:
tm = (tl+tr)//2
if i <= tm:
update(2*v, tl, tm, i, tree, segments, dp)
else:
update(2*v+1, tm+1, tr, i, tree, segments, dp)
tree[v] = [
min(tree[2*v][0], tree[2*v+1][0]),
max(tree[2*v][1], tree[2*v+1][1]),
max(tree[2*v][2], tree[2*v+1][2])
]
def query(v: int, tl: int, tr: int, x: int, tree: list):
# print(tl, tr, tree[v], x)
if x <= tree[v][0]: return 0
if x > tree[v][1]: return tree[v][2]
tm = (tl+tr)//2
a = query(2*v, tl, tm, x, tree)
b = query(2*v+1, tm+1, tr, x, tree)
return max(a, b)
def solve():
n = int(input())
tree = [[float('inf'), float('inf'), -1] for _ in range(4*n)]
dp = [1] * n
segments = []
for i in range(n):
l, r = map(int, input().split(" "))
segments.append((l, r))
upd = [[] for _ in range(n)]
for i in range(n):
# print(tree)
l, r = segments[i]
mx_j = query(1, 0, n-1, i - l, tree)
dp[i] = max(dp[i], mx_j + 1)
upd[min(n-1, i + r)].append(i)
for j in upd[i]:
update(1, 0, n-1, j, tree, segments, dp)
# print(query(1, 0, n-1, n-1, tree))
print(max(dp))
# j < i - l[i]
solve()
