//```// YF YUSUF
// #include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <set>
#include <map>
#include <unordered_map>
#include <algorithm>
#include <cmath>
#include <numeric>
#include <queue>
#include <stack>
#include <cassert>
#include <climits>
#include <string>
#include <cstdlib>
#include <random>
#include <iomanip>
#include <ctime>
using namespace std;
#ifdef YF_CHECK
bool LOCAL = 1;
#else
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize ("inline")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("O3")
bool LOCAL = 0;
#endif
using i128 = __int128;
using ll = long long;
using ld = long double;
using vll = vector <ll>;
using mll = map <ll,ll>;
using pll = pair <ll,ll>;
using vvl = vector <vll>;
using vpll = vector <pll>;
template<class T>T MIN(T&a,T b){a=min(a,b);return a;}
template<class T>T MAX(T&a,T b){a=max(a,b);return a;}
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define sgr v+v+1,(tl+tr)/2+1,tr
#define sgl v+v,tl,(tl+tr)/2
#define pb push_back
#define ins insert
#define S second
#define F first
mt19937_64 MT(time(0));
ll BP(ll a,ll b,ll mod=1e9+7){
if(b==0)return 1;
ll q=BP(a,b/2,mod);
return ((q*q)%mod*(b%2?a:1ll))%mod;
}
ll f(ll x){return x*(x+1)/2;}
ll dup(ll a,ll b){return (a+b-1)/b;}
ll lcm(ll a,ll b){return a/__gcd(a,b)*b;}
ll invf(ll x){return (-1+sqrt(1+8*x))/2;}
ll lg(ll x){return (x ? 63 - __builtin_clzll(x) : -1);}
const ll mod=998244353;
const ll INF=1e18;
const ll inf=1e9+7;
const ll N =1e6+7;
ll n;
vll x[N];
ll a[N], b[N];
int t1[N * 4], t2[N * 4];
void build (int v = 1, int tl = 1, int tr = n) {
t1[v] = inf;
t2[v] = -inf;
if (tl == tr) {
return;
}
int tm = tl + tr >> 1;
build(v << 1, tl, tm);
build(v << 1 | 1, tm + 1, tr);
}
int get1 (int l, int r, int v = 1, int tl = 1, int tr = n) {
if (l > r) return inf;
if (tl == l && tr == r) return t1[v];
int tm = tl + tr >> 1;
return min(get1(l, min(r, tm), v << 1, tl, tm), get1(max(tm + 1, l), r, v << 1 | 1, tm + 1, tr));
}
int get2 (int l, int r, int v = 1, int tl = 1, int tr = n) {
if (l > r) return -inf;
if (tl == l && tr == r) return t2[v];
int tm = tl + tr >> 1;
return max(get2(l, min(r, tm), v << 1, tl, tm), get2(max(tm + 1, l), r, v << 1 | 1, tm + 1, tr));
}
void upd1 (int pos, int val, int v = 1, int tl = 1, int tr = n) {
if (tl == tr) {
t1[v] = val;
return;
}
int tm = tl + tr >> 1;
if (pos <= tm) upd1(pos, val, v << 1, tl, tm);
else upd1(pos, val, v << 1 | 1, tm + 1, tr);
t1[v] = min(t1[v << 1], t1[v << 1 | 1]);
}
void upd2 (int pos, int val, int v = 1, int tl = 1, int tr = n) {
if (tl == tr) {
t2[v] = val;
return;
}
int tm = tl + tr >> 1;
if (pos <= tm) upd2(pos, val, v << 1, tl, tm);
else upd2(pos, val, v << 1 | 1, tm + 1, tr);
t2[v] = max(t2[v << 1], t2[v << 1 | 1]);
}
bool compX(const vll &a, const vll &b){
if(a[0] == b[0])return a[1] < b[1];
return a[0] < b[0];
}
bool compE(const vll &a, const vll &b){
return a[1] < b[1];
}
bool compI(const vll &a, const vll &b){
return a[2] < b[2];
}
void YF_MAIN(ll TEST){
cin>>n;
ll ans = 0;
for(int i=1;i<=n;i++){
x[i] = {0, 0, 0};
cin>>x[i][0]>>x[i][1];
}
sort(x+1, x+n+1, compX);
for(int i=1;i<=n;i++){
x[i][2] = i;
a[i] = (x[i][1] - x[i][0]);
b[i] = (x[i][1] + x[i][0]);
}
build();
sort(x+1, x+n+1, compE);
for(int j=n; j>=1; j--){
ll X = x[j][0];
ll E = x[j][1];
ll i = x[j][2];
bool ok = 1;
// cout<<get1(i, n)<<" "<<get2(1, i)<<", ";
if(X - E >= get1(i, n)) ok = 0;
if(X + E <= get2(1, i)) ok = 0;
if(ok) ans++;
upd1(i, X - E);
upd2(i, X + E);
}
cout<<ans;
}
const bool TECT=0;
const bool FLSH=1;
const ll SN=1e0 + 7; ll SM[SN];
const ll FN=1e0 + 7; ll FACT[FN], inv[FN], FMOD=inf;
ll PER(ll n,ll k){return FACT[n] *inv[n-k]%FMOD;}
ll CNK(ll n,ll k){return PER(n,k)*inv[k ]%FMOD;}
void BEFORE(){
for(ll i=2;i<SN;i++){
if(SM[i])continue;
for(ll j=i;j<SN;j+=i)
MAX(SM[j],i);
}
FACT[0]=inv[0]=1;
for(int i=1;i<FN;i++){
FACT[i]=FACT[i-1]*i%FMOD;
inv[i]=BP(FACT[i],FMOD-2,FMOD);
}
}
signed main(){
// freopen(("input.txt"),"r",stdin);freopen(("output.txt"),"w",stdout);
if(FLSH){
ios_base::sync_with_stdio(0);
cout.setf(ios::fixed);
cout.precision(0);
cout.tie(0);
cin.tie(0);
}
cout<<(0 && LOCAL ? "\nYF_OUTPUT:\n\n" : "");
int TEST=1;
if(TECT)
cin>>TEST;
BEFORE();
for(int T=1;T<=TEST;T++){
// cout<<"Case "<<T<<": ";
YF_MAIN(T);
cout<<(T==TEST ? "" : "\n");
}
return 0;
}
// YF YUSUF ```
