#define _USE_MATH_DEFINES
#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
#define _SILENCE_ALL_CXX17_DEPRECATION_WARNINGS
#define _CRT_SECURE_NO_WARNINGS
//#include <bits/stdc++.h>

#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <bitset>
#include <unordered_map>
#include <unordered_set>
#include <cassert>
#include <fstream>
#include <array>
#include <string>
#include <cstring>
#include <functional>
#include <ctime>
#include <iostream>
#include <unordered_set>

#include <nmmintrin.h>
#include <mmintrin.h>
#include <emmintrin.h>


using namespace std;

#define dprint(Exp,...) if(Exp){fprintf(stderr, __VA_ARGS__);}
#define printe(...) fprintf(stderr, __VA_ARGS__);
//#define printe(...) void();
#define printE(...) fprintf(stderr, __VA_ARGS__);
//#define printE(...) void();


#define PrtExp(_Exp)  cerr<< #_Exp <<" = "<< (_Exp)
#define PrtExpN(_Exp)  cerr<< #_Exp <<" = "<< (_Exp) <<"\n"

#define SINT(n) scanf("%d",&n)
#define SINT2(n,m) scanf("%d %d",&n,&m)
#define SINT3(n,m,o) scanf("%d %d %d",&n,&m,&o)
#define SINT4(n,m,o,P) scanf("%d %d %d %d",&n,&m,&o,&P)
#define SINT5(n,m,o,P,q) scanf("%d %d %d %d %d",&n,&m,&o,&P,&q)
#define SLL(n) scanf("%lld",&n)
#define SLL2(n,m) scanf("%lld %lld",&n,&m)
#define SLL3(n,m,o) scanf("%lld %lld %lld",&n,&m,&o)
#define SST(s) scanf("%s",s)
#define SCH(c) scanf("%c",&c)

#define GC() getchar()

#define PINT(n) printf("%d",(int)(n))
#define PINT2(n,m) printf("%d %d",(int)(n),(int)(m))
#define PINT3(n,m,l) printf("%d %d %d",(int)(n),(int)(m),(int)(l))
#define PLL(n) printf("%lld",(long long)(n))
#define PST(s) printf("%s",(s))
#define PCH(s) printf("%c",(s))

#define PINTN(n) printf("%d\n",(int)(n))
#define PINT2N(n,m) printf("%d %d\n",(int)(n),(int)(m))
#define PINT3N(n,m,l) printf("%d %d %d\n",(int)(n),(int)(m),(int)(l))
#define PLLN(n) printf("%lld\n",(long long)(n))
#define PSTN(s) printf("%s\n",(s))
#define PCHN(s) printf("%c\n",(s))

#define PSP() printf(" ")
#define PN() printf("\n")

#define PC(c) putchar(c)
#define CSP (' ')
#define SN ("\n")

#define rep(i,a) for(int i=0;i<a;i++)
#define reP(i,a) for(int i=0;i<=a;i++)
#define Rep(i,a) for(int i=a-1;i>=0;i--)
#define ReP(i,a) for(int i=a;i>=0;i--)

#define rEp(i,a) for(i=0;i<a;i++)
#define rEP(i,a) for(i=0;i<=a;i++)
#define REp(i,a) for(i=a-1;i>=0;i--)
#define REP(i,a) for(i=a;i>=0;i--)

#define repft(i,a,b) for(int i=a;i<b;i++)
#define repfT(i,a,b) for(int i=a;i<=b;i++)
#define Repft(i,a,b) for(int i=a-1;i>=b;i--)
#define RepfT(i,a,b) for(int i=a;i>=b;i--)

#define foreach(a,it) for(auto it = a.begin(); it != a.end(); ++it)

#define FILL(a,v) fill(begin(a),end(a), v)
#define FILL0(a) memset(a,0,sizeof(a))
#define FILL1(a) memset(a,-1,sizeof(a))

typedef long long ll;

typedef unsigned long long ull;
typedef pair<int, int> Pi;
typedef pair<ll, ll>   Pll;


const int INF = 1'010'000'000; // 0x3C33'6080
const ll INFLL = 0x1f1f1f1f1f1f1f1fLL;//2,242,545,357,980,376,863

template <class A, class B> inline ostream& operator<<(ostream& st, const pair<A, B>& P) { return st << "(" << P.first << "," << P.second << ")"; };
template <class A, class B> inline pair<A, B> operator+(const pair<A, B>& P, const pair<A, B>& Q) { return pair<A, B>(P.first + Q.first, P.second + Q.second); };
template <class A, class B> inline pair<A, B> operator-(const pair<A, B>& P, const pair<A, B>& Q) { return pair<A, B>(P.first - Q.first, P.second - Q.second); };

#define fs  first
#define sc  second

int bitCount(unsigned long long bits) {
#if _MSC_VER >= 1920 || __INTEL_COMPILER
	return _mm_popcnt_u64(bits);
#else
	return __builtin_popcountll(bits);
#endif 
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }




template <class T>
struct fenwick_tree {
	int n;
	std::vector<T> x;
	fenwick_tree(int n_ = 0) : n(n_), x(n + 1, 0) {}
	int size() const { return n; }
	T sum(int r) const {
		T S = 0; ++r;
		for (r = r - 1; r >= 0; r = (r & (r + 1)) - 1) S += x[r];
		return S;
	}
	T sum(int l, int r) const { return sum(r) - sum(l); }
	void add(int k, const T& a) {
		for (; k < n; k |= k + 1) x[k] += a;
	}
	void set(int k, const T& a) { add(k, a - sum(k, k + 1)); }
};




int solve(vector<Pll> in) {
	const int n = in.size();
	vector<Pll> v; // {end, start}
	rep(i, n) {
		v.push_back({ in[i].first + in[i].second, in[i].first - in[i].second });
	}
	//sort(v.begin(), v.end(), greater<Pll>());
	sort(v.begin(), v.end());
	int ret = 0;
	ll t = -INFLL;
	for (auto a : v) {
		//cerr << a << endl;
		if (t <= a.second) {
			++ret;
			t = a.first;
		}
	}
	return ret;
}

int solve2(vector<Pll> in) {
	const int n = in.size();
	vector<Pll> v; // {end, start}
	rep(i, n) {
		v.push_back({ in[i].first - in[i].second, in[i].first + in[i].second });
	}
	sort(v.begin(), v.end());
	int ret = 0;
	rep(f, (1 << n)) {
		ll t = -INFLL;
		bool ok = true;
		rep(i, n) {
			if (((f >> i) & 1) == 0) continue;
			//cout << v[i];

			if (t <= v[i].first) {
				t = v[i].second;
			} else {
				ok = 0; break;
			}
		}
		//cout << endl;
		
		if (ok) {
			ret = max(ret, bitCount(f));
			/*
			rep(i, n) {
				if (((f >> i) & 1) == 0) continue;
				cout << v[i];
			}
			cout << endl;
			*/
		}
	}
	return ret;
}



void test() {
	const int n = 4;
	const int a = 10;
	const int b = 10;
	for(;;){
		vector<Pll> in(n);
		rep(i, n) {
			bool ng;
			do {
				in[i].first = abs(rand()) % a;
				ng = false;
				rep(j, i) {
					if (in[j].first == in[i].first) {
						ng = true;
					}
				}
			} while (ng);

			in[i].second = abs(rand()) % b + 1;

		}
		int r1 = solve(in);
		int r2 = solve2(in);
		if (r1 != r2) {
			rep(i, n) {
				cout << in[i] << endl;
			}
			cout << "! " << r1 << " " << r2 << endl;
			return;
		}

	}

}


int main() {
	//test();


	int n;
	cin >> n;
	vector<Pll> in(n);
	rep(i, n) {
		ll x, l;
		cin >> x >> l;
		in[i] = { x, l };
	}
	int ret = solve(in);
	cout << ret << endl;

}


Measured memory_bytes: 5492