// author : anhtun_hi , nqg
#include <bits/stdc++.h>
#define ll long long
#define ii pair<ll, ll>
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define reset(h, v) memset(h, v, sizeof h)
#define Forv(i, a) for(auto& i : a)
#define For(i, a, b) for(int i = a; i <= b; ++i)
#define Ford(i, a, b) for(int i = a; i >= b; --i)
#define c_bit(i) __builtin_popcountll(i)
#define Bit(mask, i) ((mask >> i) & 1LL)
#define onbit(mask, i) ((mask) bitor (1LL << i))
#define offbit(mask, i) ((mask) &~ (1LL << i))
using namespace std;
namespace std {
template <typename T, int D>
struct _vector : public vector <_vector <T, D - 1>> {
static_assert(D >= 1, "Dimension must be positive!");
template <typename... Args>
_vector(int n = 0, Args... args) : vector <_vector <T, D - 1>> (n, _vector <T, D - 1> (args...)) {}
};
template <typename T> struct _vector <T, 1> : public vector <T> {
_vector(int n = 0, const T& val = T()) : vector <T> (n, val) {}
};
template <class A, class B> bool minimize(A &a, B b){return a > b ? a = b, true : false;}
template <class A, class B> bool maximize(A &a, B b){return a < b ? a = b, true : false;}
}
const int dx[] = {0, 0, +1, -1}, dy[] = {-1, +1, 0, 0}, LOG = 20, base = 311, inf = 1e9 + 5;
const int MAXN = 5e5 + 5;
const ll mod = 1e9 + 7;
const ll oo = 1e18;
//#define int long long
int n, b[MAXN], dp[MAXN], bit[MAXN];
ii a[MAXN];
int st[MAXN << 2];
void build(int id, int l, int r){
if (l == r) return void(st[id] = b[l]);
int mid = l + r >> 1;
build(id << 1, l, mid);
build(id << 1 | 1, mid + 1, r);
st[id] = max(st[id << 1], st[id << 1 | 1]);
}
int get(int id, int l, int r, int u, int v){
if (v < l || r < u) return -inf;
if (u <= l && r <= v) return st[id];
int mid = l + r >> 1;
return max(get(id << 1, l, mid, u, v), get(id << 1 | 1, mid + 1, r, u, v));
}
void Solve() {
cin >> n;
For(i, 1, n) {
int x, e; cin >> x >> e;
a[i] = {e - x, e + x};
}
sort(a + 1, a + n + 1);
stack<ii> st;
For(i, 1, n) {
while(st.size() && st.top().fi <= a[i].fi && st.top().se <= a[i].se) st.pop();
st.push(a[i]);
}
cout << st.size() << '\n';
}
int32_t main() {
cin.tie(0) -> sync_with_stdio(0);
if(fopen("a.inp", "r")) {
freopen("a.inp", "r", stdin);
freopen("a.out", "w", stdout);
}
int t = 1;
// cin >> t;
for (int test = 1; test <= t; test++) {
Solve();
}
return 0;
}
