#ifdef LOCAL
#include "/home/bgopc/template/pch.hpp"
#endif
#include <bits/stdc++.h>
using namespace std;
// * No One Dies a Virgin, Life Fucks Us All
typedef long long ll;
#define nl '\n'
#define ff first
#define ss second
#define pb push_back
#define sik(x) {cout << x << nl; return;}
constexpr ll maxn = 5e5+10, mod = 1e9 + 7, inf = 1e17, SQ = 450, LG = 20;
typedef pair<int, int> pii;
int n;
pii a[maxn];
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n;
for (int i = 1 , x , e ; i <= n ; i ++) {
cin >> x >> e;
a[i] = {x - e, x + e};
}
sort(a + 1, a + n + 1, [&] (const pii& x, const pii& y) {
if (x.ff == y.ff) return x.ss > y.ss;
else return x.ff < y.ff;
});
int ans = 0;
ll r = -inf;
for (int i = 1 ; i <= n ; i ++) {
if (a[i].ss > r) {
++ ans;
r = a[i].ss;
}
}
cout << ans << nl;
}
