#define _USE_MATH_DEFINES
#include<iostream>
#include<string>
#include<queue>
#include<cmath>
#include<map>
#include<set>
#include<list>
#include<iomanip>
#include<vector>
#include<random>
#include<functional>
#include<algorithm>
#include<stack>
#include<cstdio>
#include<bitset>
#include<unordered_map>
#include<climits>
#include<fstream>
using namespace std;
///////////////////library zone!!!!!!!!!!!!!!!!!!!!!!!!!!!!
typedef long long ll;
typedef long double ld;
#define all(a) (a).begin(),(a).end()
#define EPS (1e-5)
#define bit(n,k) ((n>>k)&1)
const ll Mod = 1000000007;
const ll mod = 998244353;
struct H {
ll x, y;
bool operator<(const H& b) const {
if (x != b.x) return x < b.x;
return y < b.y;
}
bool operator>(const H & b) const {
if (x != b.x) return x > b.x;
return y > b.y;
}
bool operator==(const H & b) const { return x == b.x && y == b.y; }
bool operator!=(const H & b) const { return (*this) != b; }
};
struct P {
ll pos, cost;
bool operator<(const P& b) const { return cost < b.cost; }
bool operator>(const P& b) const { return cost > b.cost; }
};
struct B {
ll to, cost;
};
struct E {
ll from, to, cost;
bool operator<(const E& b) const { return cost < b.cost; }
bool operator>(const E& b) const { return cost > b.cost; }
};
template<typename T, typename U>
void chmin(T & a, U b) {
if (a > b) a = b;
}
template<typename T, typename U>
void chmax(T & a, U b) {
if (a < b) a = b;
}
template<typename T>
T max_0(T a) {
if (a < 0) return 0;
return a;
}
template<typename T>
T min_0(T a) {
if (a > 0) return 0;
return a;
}
ll read() {
ll u;
ll k = scanf("%lld", &u);
return u;
}
ll gcd(ll i, ll j) {
if (i > j) swap(i, j);
if (i == 0) return j;
return gcd(j % i, i);
}
ll mod_pow(ll x, ll n, ll p) {
ll res = 1;
while (n > 0) {
if (n & 1) res = res * x % p;
x = x * x % p;
n >>= 1;
}
return res;
}//x^n%p
const ll Inf = 3023372036854775807;
const int inf = 1500000000;
#define int long long
//----------------------------------------------------
int n;
struct A {
int x, r;
bool operator<(A b) {
if (x + r != b.x + b.r) return x + r < b.x + b.r;
return x - r < b.x - b.r;
}
};
A a[1000000];
vector<int>v;
int dat[1000000];
int m = 1;
void update(int x, int t) {
x += m - 1;
dat[x] = t;
while (x > 0) {
x = (x - 1) / 2;
dat[x] = max(dat[x + 2 + 1], dat[x * 2 + 2]);
}
}
int query(int i, int a, int b, int l, int r) {
if (b <= l || r <= a) return 0;
if (a <= l && r <= b) {
return dat[i];
}
return max(query(i * 2 + 1, a, b, l, (l + r) / 2),
query(i * 2 + 2, a, b, (l + r) / 2, r));
}
signed main() {
cin >> n;
for (int i = 0; i < n; i++) {
cin >> a[i].x >> a[i].r;
v.push_back(a[i].x + a[i].r);
v.push_back(a[i].x - a[i].r);
}
sort(a, a + n);
int t = 0;
for (int i = 0; i < n; ) {
int j = i;
while (a[i].x + a[i].r == a[j].x + a[j].r)
j++;
a[t++] = a[i];
i = j;
}
n = t;
sort(all(v));
v.erase(unique(all(v)), v.end());
while (m < n) m *= 2;
int ans = 0;
for (int i = 0; i < n; i++) {
int s = upper_bound(all(v), a[i].x - a[i].r) - v.begin();
int e = lower_bound(all(v), a[i].x - a[i].r) - v.begin();
int k = query(0, s, m, 0, m);
ans = max(ans, k + 1);
update(e, k + 1);
}
cout << ans << endl;
}