#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
const int MaxN = 1e6 + 5;
bool cmp(pair<long long, long long> a, pair<long long, long long> b)
{
if (a.first == b.first)
{
return a.second > b.second;
}
return a.first < b.first;
}
int n;
pair<long long, long long> arr[MaxN];
void Inp()
{
cin >> n;
for (int x = 1; x <= n; x++)
{
cin >> arr[x].first >> arr[x].second;
arr[x] = make_pair(arr[x].first - arr[x].second, arr[x].first + arr[x].second);
}
sort(arr + 1, arr + n + 1, cmp);
}
void Exc()
{
int res = 0;
for (int x = 1; x <= n; x++)
{
int y = x;
while (y <= n && arr[x].second >= arr[y].second)
{
y++;
}
y--;
res++;
x = y;
}
cout << res;
}
int main()
{
//freopen("B.INP", "r", stdin);
//freopen("B.OUT", "w", stdout);
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int test = 1;
//cin >> test;
for (int x = 1; x <= test; x++)
{
Inp();
Exc();
}
return 0;
}
