#include <bits/stdc++.h>
#define ll long long
using namespace std;
struct item {
	ll x,y,z;
};
bool comp(item item1, item item2){
	if (item1.y!=item2.y){
		return item1.y<item2.y;
	}
	if (item1.x!=item2.x){
		return item1.x<item2.x;
	}
	return item1.z<item2.z;
}
int main() {
	// your code goes here
	ll n;
	cin>>n;
	vector <item> a(n);
	for (ll i=0;i<n;i++){
		ll t;
		cin>>a[i].x>>t;
		a[i].y=t+a[i].x;
		a[i].z=i;
	}
	sort(a.begin(),a.end(),comp);
	ll ans=0,max=a[0].x;
	for (ll i=0;i<n;i++){
		if (max<=a[i].x){
			ans++;
			max=a[i].y;
		}
	}
	cout<<ans;
	return 0;
}

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NQoxIDIKMiAzCjEgMgozIDEKMyAy

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3 1
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