#include <bits/stdc++.h>
#ifdef LOCAL_DEBUG
#define DEBUG 1
#define CERR if(DEBUG) cerr
#define MACRO(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,NAME,...) NAME
#define pr(...) CERR<<MACRO(__VA_ARGS__,pr10,pr9,pr8,pr7,pr6,pr5,pr4,pr3,pr2,pr1)(__VA_ARGS__)<<endl
#define pr1(a) (#a)<<"="<<(a)<<" "
#define pr2(a,b) pr1(a)<<pr1(b)
#define pr3(a,b,c) pr1(a)<<pr2(b,c)
#define pr4(a,b,c,d) pr1(a)<<pr3(b,c,d)
#define pr5(a,b,c,d,e) pr1(a)<<pr4(b,c,d,e)
#define pr6(a,b,c,d,e,f) pr1(a)<<pr5(b,c,d,e,f)
#define pr7(a,b,c,d,e,f,g) pr1(a)<<pr6(b,c,d,e,f,g)
#define pr8(a,b,c,d,e,f,g,h) pr1(a)<<pr7(b,c,d,e,f,g,h)
#define pr9(a,b,c,d,e,f,g,h,i) pr1(a)<<pr8(b,c,d,e,f,g,h,i)
#define pr10(a,b,c,d,e,f,g,h,i,j) pr1(a)<<pr9(b,c,d,e,f,g,h,i,j)
#define prArr(a){CERR<<(#a)<<"={";int i=0;for(auto t:(a))CERR<<(i++?", ":"")<<t;CERR<<"}"<<endl;}
#else
#define DEBUG 0
#define pr(...)
#define prArr(a)
#endif
using namespace std;
using Int = long long;
using _int = int;
using ll = long long;
using Double = long double;
const Int INF = (1LL<<60)+1e9; // ~ 1.15 * 1e18
const Int mod = (1e9)+7;
const Double EPS = 1e-8;
const Double PI = 6.0 * asin((Double)0.5);
using P = pair<Int,Int>;
template<class T> T Max(T &a,T b){return a=max(a,b);}
template<class T> T Min(T &a,T b){return a=min(a,b);}
template<class T1, class T2> ostream& operator<<(ostream& o,pair<T1,T2> p){return o<<"("<<p.first<<","<<p.second<<")";}
template<class T1, class T2, class T3> ostream& operator<<(ostream& o,tuple<T1,T2,T3> t){return o<<"("<<get<0>(t)<<","<<get<1>(t)<<","<<get<2>(t)<<")";}
template<class T1, class T2> istream& operator>>(istream& i,pair<T1,T2> &p){return i>>p.first>>p.second;}
template<class T> ostream& operator<<(ostream& o,vector<T> a){Int i=0;for(T t:a)o<<(i++?" ":"")<<t;return o;}
template<class T> istream& operator>>(istream& i,vector<T> &a){for(T &t:a)i>>t;return i;}
//INSERT ABOVE HERE

template <typename T>
class Compress{
public:
  vector<T> X;
  bool ok;
  Compress():ok(false){};
  Int size(){return X.size();}
  void add(T a){ok = false; X.push_back(a);X.push_back(a-1); X.push_back(a+1);}
  void add(const vector<T> a){for(T x:a) add(x);}
  //void add(const vector<T> &a){for(T x:a) add(x);}

  void build(){
    ok = true;
    sort(X.begin(),X.end());
    X.erase(unique(X.begin(),X.end()),X.end());
  }

  T getL(T x){assert(ok); return lower_bound(X.begin(),X.end(),x) - X.begin();}
  T getU(T x){assert(ok); return upper_bound(X.begin(),X.end(),x) - X.begin();}
};


signed main(){
  srand((unsigned)time(NULL));
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  cout << fixed << setprecision(12);

  Int N;
  cin>>N;
  vector<P> A;
  Compress<Int> cmp;
  for(Int i=0;i<N;i++){
    Int X, L;
    cin>>X>>L;
    Int l = X - L + 1;
    Int r = X + L - 1;
    A.push_back(P(l, r));
    cmp.add(l);
    cmp.add(r);
  }
  cmp.build();
  sort(A.begin(), A.end());
  vector<Int> dp(cmp.size()+10, 0);
  Int idx = 0;
  for(Int i=0;i<cmp.size()+8;i++){
    Max(dp[i+1], dp[i]);
    while(idx < (Int)A.size() && A[idx].first == cmp.X[i]){
      Int l = cmp.getL(A[idx].first);
      Int r = cmp.getU(A[idx].second);
      idx++;
      Max(dp[r + 1], dp[i] + 1);
    }
  }
  assert(idx == N);
  Int ans = 0;
  for(Int d:dp) Max(ans, d);
  cout<<ans<<endl;

  return 0;
}


Measured memory_bytes: 15208