/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author
 */

// Created by White Knife on 15/04/20.
// doot diddly donger cuckerino Hahahahahah

#pragma GCC optimize("O3")
#pragma GCC target("sse4")
#pragma GCC target("popcnt")


#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;
using namespace __gnu_cxx;
using namespace std;

// @formatter:off
#define F               first
#define S               second
#define all(x)          (x).begin(), (x).end()
#define sz(x)           int((x).size())
#define sim             template<typename T
#define ris             return *this
#define dor             > debug & operator <<
#define eni(x)          sim > typename enable_if<sizeof dud<T>(0) x 1, debug&>::type operator<<(T i)
sim> struct rge { T b, e; };
sim> rge<T> rang(T i, T j) { return rge<T>{i, j}; }
sim> auto dud(T *x) -> decltype(cerr << *x, 0);
sim> char dud(...);
struct debug {
#ifdef LOCAL
  ~debug() { cerr << endl; }
  eni(!=) { cerr << boolalpha << i; ris; }
  eni(==) { ris << rang(all(i)); }
  sim, typename U dor(pair<U, T> d) { ris << "(" << d.first << ", " << d.second << ")"; }
  sim dor(rge<T> d) { *this << "["; for (auto it = d.b; it != d.e; ++it) *this << ", " + 2 * (it == d.b) << *it; ris << "]"; }
#else
  sim dor(const T&) { ris; }
#endif
};
#define pr(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

using ll = long long;
using ull = unsigned long long;
using ld = long double;
//using li = __int128;
//using uli = unsigned __int128;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vb = vector<bool>;

using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vpii = vector<pii>;
using vpll = vector<pll>;
template <typename T> using ordered_set = tree<T, null_type, less<>, rb_tree_tag, tree_order_statistics_node_update>;

const ld PI = acos(-1);

template<typename T> inline T mini(T& x, T y) { return x = min(x, y); }
template<typename T> inline T maxi(T& x, T y) { return x = max(x, y); }
template <typename T> T rand(T x, T y) { return rand() % (y - x + 1) + x; }
mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
template <typename T>
T gcd(T a, T b) {
  a = abs(a);
  b = abs(b);
  while (b != 0) {
    a = a % b;
    swap(a, b);
  }
  return a;
}
// @formatter:on


class BRobotArms {
public:
  
  void solveOne(istream& cin, ostream& cout) {
  
  }
  
  void solve(std::istream& cin, std::ostream& cout) {
    int n;
    cin >> n;
    vector<pii> vec(n);
    for (int i = 0; i < n; ++i) {
      cin >> vec[i].F >> vec[i].S;
      auto temp = vec[i];
      vec[i].F = temp.F - temp.S;
      vec[i].S = temp.F + temp.S;
    }
    sort(all(vec), [&](auto p1, auto p2) { return (p1.S != p2.S) ? p1.S < p2.S : (p1.F < p2.F); });
    debug() << pr(vec);
    int cnt = 1;
    int end = vec[0].S;
    for (int i = 1; i < n; ++i) {
      int curr = vec[i].F;
      if (curr >= end) {
        ++cnt;
        end = vec[i].S;
      }
    }
    cout << cnt << '\n';
  }
};

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);
	BRobotArms solver;
	std::istream& in(std::cin);
	std::ostream& out(std::cout);
	solver.solve(in, out);
	return 0;
}


Measured memory_bytes: 1024