#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define PUT(a, b) freopen(a, "r", stdin); freopen(b, "w", stdout);
#define all(a) a.begin(), a.end()
#define answerNO {cout << "NO" << endl;}
#define answerYES {cout << "YES" << endl;}
using namespace std;
#define ff first
#define ss second
#define pb push_back
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
ll mod = 1e9 + 7;
void solve(){
ll n; cin >> n;
VPL a(n);
rep(i, n){
ll l, r; cin >> l >> r;
a[i] = {min(n - 1, i + r), max(0ll, i - l)};
}
sort(all(a));
int ans = 0, last = -1;
rep(i, n){
if(a[i].ss > last){
ans++;
last = a[i].ff;
}
}
cout << max(ans, 1) << "\n";
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL), cout.tie(NULL);
//PUT("traffic.in", "traffic.out");
int t = 1;
//cin >> t;
while(t--){
solve();
}
}
