#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;
typedef pair<int, int> pii;
const int INF = 2e9 + 5;
struct SMT{
int n;
vector<int> tree;
SMT(int n = 0){
this->n = n;
this->tree.assign(n<<2|3, INF);
}
void update(int pos, int val){
int id = 1;
for(int lo=1, hi=n; lo<hi;){
int mid = (lo + hi)>>1;
if(pos <= mid) hi = mid, id = id<<1;
else lo = mid + 1, id = id<<1|1;
}
tree[id] = val;
for(id>>=1; id; id>>=1) tree[id] = min(tree[id<<1], tree[id<<1|1]);
}
void get(int l, int r, int id, const int &pos, const int &val, vector<int> &vt){
if(tree[id] > val || l >= pos) return;
if(l == r){
vt.push_back(l);
return;
}
int mid = (l + r)>>1;
get(l, mid, id<<1, pos, val, vt);
get(mid + 1, r, id<<1|1, pos, val, vt);
}
void get(int pos, int val, vector<int> &vt){
get(1, n, 1, pos, val, vt);
}
void rget(int l, int r, int id, const int &pos, const int &val, vector<int> &vt){
if(tree[id] > val || r <= pos) return;
if(l == r){
vt.push_back(l);
return;
}
int mid = (l + r)>>1;
rget(l, mid, id<<1, pos, val, vt);
rget(mid + 1, r, id<<1|1, pos, val, vt);
}
void rget(int pos, int val, vector<int> &vt){
rget(1, n, 1, pos, val, vt);
}
};
const int MX = 500005;
int n;
pii a[MX];
int b[MX];
bitset<MX> used = 0;
void nhap(){
cin >> n;
for(int i=1; i<=n; i++){
cin >> a[i].fi >> a[i].se;
}
}
void solve(){
for(int i=1; i<=n; i++) b[i] = i;
sort(a + 1, a + 1 + n);
sort(b + 1, b + 1 + n, [&](const int &x, const int &y) -> bool {return a[x].se > a[y].se;});
SMT pf(n), sf(n);
for(int i=1; i<=n; i++){
pf.update(i, a[i].se - a[i].fi);
sf.update(i, a[i].fi + a[i].se);
}
int ans = 0;
for(int j=1; j<=n; j++) if(!used[b[j]]){
int i = b[j];
ans++;
used[i] = 1;
pf.update(i, INF);
sf.update(i, INF);
vector<int> vt;
pf.get(i, a[i].se - a[i].fi, vt);
sf.rget(i, a[i].fi + a[i].se, vt);
for(int x: vt){
pf.update(x, INF);
sf.update(x, INF);
used[x] = 1;
}
}
cout << ans;
}
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
nhap();
solve();
return 0;
}
