#include <bits/stdc++.h>
using namespace std;
template <class T1, class T2>
bool maximize (T1 &a, T2 b) {
if (a < b) {a = b; return true;}
return false;
}
template <class T1, class T2>
bool minimize (T1 &a, T2 b) {
if (a > b) {a = b; return true;}
return false;
}
#define FOR(i, a, b) for(int i = a; i <= (int)b; i++)
#define FORD(i, a, b) for(int i = a; i >= (int)b; i--)
#define MASK(i) (1LL << (i))
#define BIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
const int MAXN = 5e5 + 5;
int n;
array <int, 2> a[MAXN];
void init(void) {
cin >> n;
FOR(i, 1, n) cin >> a[i][0] >> a[i][1];
sort (a + 1, a + 1 + n);
}
pair <int, int> line[MAXN];
vector <int> g[MAXN];
bool vis[MAXN];
void dfs(int u) {
if (vis[u]) return;
vis[u] = 1;
for (int &v : g[u]) {
dfs(v);
}
}
void process(void) {
FOR(i, 1, n) {
line[i].first = a[i][0] - a[i][1];
line[i].second = a[i][0] + a[i][1];
}
sort (line + 1, line + 1 + n, [&] (pair <int, int> u, pair <int, int> v) {
if (u.first == v.first) return u.second > v.second;
return u.first < v.first;
});
// FOR(i, 1, n) {
// cout << line[i].first << " " << line[i].second << "\n";
// }
FOR(i, 1, n) {
FOR(j, 1, i) {
if (line[j].first <= line[i].first && line[i].second <= line[j].second) {
g[j].push_back(i);
/// cout << j << " " << i << "\n";
break;
}
}
}
int ans = 0;
FOR(i, 1, n) if (!vis[i]) {
ans++;
dfs(i);
}
cout << ans;
}
signed main(void) {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
#define taskname "kieuoanh"
if (fopen(taskname".inp", "r")) {
freopen(taskname".inp", "r", stdin);
freopen(taskname".out", "w", stdout);
}
init();
process();
cerr << "\n[Time elapsed] " << clock() << " ms!\n";
return 0;
}
/*
4
4 2
2 3
3 4
6 5
*/
