#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef long double ld;
typedef vector<ll> vi;
typedef pair<ll, ll> pi;
#define FOR(i, j, k) for (ll i = j; i < (ll) k; ++i)
#define FORD(i, j, k) for (ll i = j; i >= (ll) k; --i)
#define nl "\n"
#define sp " "
#define all(x) (x).begin(), (x).end()
#define sc second
#define fr first
#define pb emplace_back
void solve()
{
ll n;
cin >> n;
ll x[n], y[n];
FOR(i, 0, n) {
cin >> x[i] >> y[i];
}
vector<array<ll, 3>> a(n);
for(int i = 0; i < n; ++i) {
a[i] = {x[i], y[i], i};
}
sort(all(a), [&](array<ll, 3> lhs, array<ll, 3> rhs) {
return lhs[1] > rhs[1];
});
ll ans = 0;
bool covered[n] = {};
for(int i = 0; i < n; ++i) {
if(covered[a[i][2]]) continue;
covered[a[i][2]] = true;
++ans;
for(int j = a[i][2] - 1; j >= 0; --j) {
if(abs(a[i][0] - x[j]) <= a[i][1] - y[j]) {
covered[j] = true;
}
}
for(int j = a[i][2] + 1; j < n; ++j) {
if(abs(a[i][0] - x[j]) <= a[i][1] - y[j]) {
covered[j] = true;
}
}
}
cout << ans << nl;
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
ll t = 1;
// cin >> t;
while (t--)
{
solve();
}
}
