#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define fi first
#define si second
#define ar array
#define pb push_back
typedef pair<ll,ll> pi;
typedef tuple<int,int,int> ti;
typedef vector<int> vi;
template<typename T> bool chmin(T &a, T b){return (b < a) ? a = b, 1 : 0;}
template<typename T> bool chmax(T &a, T b){return (b > a) ? a = b, 1 : 0;}
void debug_out() {cerr<<endl;}
template <typename Head, typename... Tail>
void debug_out(Head _H, Tail... _T) {cerr<<" "<<to_string(_H);debug_out(_T...);}
#define debug(...) cerr<<"["<<#__VA_ARGS__<<"]:",debug_out(__VA_ARGS__)
int n;
vector<pi> rr;
stack<pi> st;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin.exceptions(ios::badbit|ios::failbit);
cin >> n;
for (int i = 1; i <= n; ++i) {
int x,e; cin >> x >> e;
rr.pb({x-e, x+e});
}
sort(rr.begin(), rr.end(), [](pi a, pi b) {
if (a.si == b.si) return a.fi < b.fi;
return a.si < b.si;
});
for (auto [s, e]: rr) {
while (st.size() && st.top().fi >= s) st.pop();
st.push({s, e});
}
cout << (int)st.size();
return 0;
}
