// Author: caption_mingle
#include "bits/stdc++.h"
using namespace std;
#define ln "\n"
#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define ll long long
const int mod = 1e9 + 7;
const int inf = 2e9;
const int N = 5e5 + 7;
int n, f[N];
pair<int, int> a[N];
vector<int> vx, vy;
struct SEGTREE {
vector<int> st;
int n;
SEGTREE() {}
SEGTREE(int n) : n(n) {
st.resize(n * 4 + 4, 0);
}
void update(int i, int l, int r, int u, int x) {
if(l > u or r < u) return ;
if(l == r) {
st[i] = x;
return;
}
int m = (l + r) >> 1;
update(i * 2, l, m, u, x);
update(i * 2 + 1, m + 1, r, u, x);
st[i] = max(st[i * 2], st[i * 2 + 1]);
}
int get(int i, int l, int r, int u, int v) {
if(l > v or r < u) return 0;
if(u <= l and r <= v) return st[i];
int m = (l + r) >> 1;
return max(get(i * 2, l, m, u, v), get(i * 2 + 1, m + 1, r, u, v));
}
};
signed main() {
cin.tie(0) -> sync_with_stdio(0);
#define task ""
if(fopen(task ".INP", "r")) {
freopen(task ".INP", "r", stdin);
freopen(task ".OUT", "w", stdout);
}
cin >> n;
for(int i = 1; i <= n; i++) {
int x, e; cin >> x >> e;
a[i].fi = e - x;
a[i].se = e + x;
vx.pb(e - x);
vy.pb(e + x);
}
sort(all(vx));
vx.erase(unique(all(vx)), vx.end());
sort(all(vy));
vy.erase(unique(all(vy)), vy.end());
for(int i = 1; i <= n; i++) {
a[i].fi = upper_bound(all(vx), a[i].fi) - vx.begin();
a[i].se = upper_bound(all(vy), a[i].se) - vy.begin();
}
sort(a + 1, a + n + 1);
int m = sz(vy);
SEGTREE st(m);
for(int i = 1; i <= n; i++) {
int pre = st.get(1, 1, m, a[i].se + 1, m);
f[i] = f[pre] + 1;
st.update(1, 1, m, a[i].se, i);
}
cout << f[n];
cerr << "\nTime: " << clock() * 1000 / CLOCKS_PER_SEC;
}
