In a factory, there are N robots placed on a number line. Robot i is placed at coordinate X_i and can extend its arms of length L_i in both directions, positive and negative.

We want to remove zero or more robots so that the movable ranges of arms of no two remaining robots intersect. Here, for each i (1 \leq i \leq N), the movable range of arms of Robot i is the part of the number line between the coordinates X_i - L_i and X_i + L_i, excluding the endpoints.

Find the maximum number of robots that we can keep.

Constraints

* 1 \leq N \leq 100,000
* 0 \leq X_i \leq 10^9 (1 \leq i \leq N)
* 1 \leq L_i \leq 10^9 (1 \leq i \leq N)
* If i \neq j, X_i \neq X_j.
* All values in input are integers.

Input

Input is given from Standard Input in the following format:


N
X_1 L_1
X_2 L_2
\vdots
X_N L_N


Output

Print the maximum number of robots that we can keep.

Examples

Input

4
2 4
4 3
9 3
100 5


Output

3


Input

2
8 20
1 10


Output

1


Input

5
10 1
2 1
4 1
6 1
8 1


Output

5
//繰り返し二乗法 repow(b,p)(b,p,modder)
//ユークリッド互除法で最大公約数 gcd
//gcdで最小公倍数 lcm
//約数列挙divList(int)
//約数列挙divSet(int)
//素数判定iP(long)とtameshiwari(long)
//二項係数クラスNCK
////NCK(max,modder)
////pre(max,modder)
////nCk(n,k)
//BSA()()()(List<T>,T,int,int,Comparator<T>)
//BSF()()()(List<T>,T,int,int,Comparator<T>)
//BSL()()()(List<T>,T,int,int,Comparator<T>)
//BSA()()()(T[],T,int,int,Comparator<T>)
//BSF()()()(T[],T,int,int,Comparator<T>)
//BSL()()()(T[],T,int,int,Comparator<T>)
//BSA()()()(int[],int,int,int,syojun)
//BSF()()()(int[],int,int,int,syojun)
//BSL()()()(int[],int,int,int,syojun)
//int kmp(String t,String p)
//文字列文字ソートStSort(String)
//二次元整数座標オブジェクトXy
////マンハッタン距離manht(Xy)
////toString
////偏角ソート用hencom
////偏角henkaku
////equals
//ユニオンファインドUnFd
////boolean isRoot(i)
////int rootOf(i)
////boolean ud(i,j)
////boolean marge(i,j)
////int[] roots()
//next_permutation(int[])
//next_bits(boolean[])
//スキャナーScnr
////next nextBuilder nextInt nextLong nextDouble()
////nextAInt nextALong nextADouble(n)(a[],n)(a[],off,len)
////nextLInt nextLLong nextLDouble(n)
//static PrintWriter out = new PrintWriter(System.out);
import java.util.*;
import java.io.*;

public class Main{
  static int repow(int b,int p){
    long a = b;
    long res=1;
    while(p>0){
      if(p%2==1){
        res*=a;
      }
      a*=a;
      p/=2;
    }
    return (int)res;
  }
  static int repow(int b,int p,int modder){
    long a = b%modder;
    long res=1;
    while(p>0){
      if(p%2==1){
        res=(res*a)%modder;
      }
      a=(a*a)%modder;
      p/=2;
    }
    return (int)res;
  }
  static long repow(long b,long p){
    long a = b;
    long res=1;
    while(p>0){
      if(p%2==1){
        res*=a;
      }
      a*=a;
      p/=2;
    }
    return res;
  }
  static long repow(long b,long p,long modder){
    long a = b%modder;
    long res=1;
    while(p>0){
      if(p%2==1){
        res=(res*a)%modder;
      }
      a=(a*a)%modder;
      p/=2;
    }
    return res;
  }
  static long gcd(long c,long d){
    while(true){
      long f=c%d;
      if(f==0){
        return d;
      }
      c=d;
      d=f;
    }
  }
  static long lcm(long c,long d){
    return c/gcd(c,d)*d;
  }
  static ArrayList<Integer> divList(int n){
    ArrayList<Integer> div=new ArrayList<Integer>();
    for(int i=1;i*i<=n;i++){
      if(n%i==0){
        div.add(i);
        if(i*i!=n){
          div.add((int)(n/i));
        }
      }
    }
    return div;
  }
  static HashSet<Integer> divSet(int n){
    HashSet<Integer> div=new HashSet<Integer>();
    for(int i=1;i*i<=n;i++){
      if(n%i==0){
        div.add(i);
        div.add((int)(n/i));
      }
    }
    return div;
  }
  static boolean iP(long n){
    if(n==2){
      return true;
    }
    if((n&1)==0||n==1){
      return false;
    }
//    if(n>3037007383L){
    if(n>Integer.MAX_VALUE){
      return tameshiwari(n);
    }
    long d=n-1;
    int s=0;
    while((d&1)==0){
      d/=2;
      s++;
    }
    int[] aa = {2,3,5,7,11,13,17};
    for(int i=0;i<7&&aa[i]<n;i++){
      int a = aa[i];
      long t = d;
      long y=repow(a,t,n);
      while(t!=n-1&&y!=1&&y!=n-1){
        y = (y*y)%n;
        t=t<<1;
      }
      if(y!=n-1&&(t&1)==0){
        return false;
      }
    }
    return true;
  }
  static boolean tameshiwari(long n){
    for(long i=2;i*i<=n;i++){
      if(n%i==0){
        return false;
      }
    }
    return true;
  }
  static class NCK{
    int max;
    int modder;
    long[] fac;
    long[] finv;
    long[] inv;
    NCK(){
      this(510000,1000000007);
    }
    NCK(int max,int modder){
      this.max=max;
      this.modder=modder;
      pre();
    }
    void pre(){
      fac = new long[max];
      finv = new long[max];
      inv = new long[max];
      fac[0]=fac[1]=1;
      finv[0]=finv[1]=1;
      inv[1]=1;
      for(int i=2;i<max;i++){
        fac[i]=fac[i-1]*i%modder;
        inv[i]=modder-inv[modder%i]*(modder/i)%modder;
        finv[i]=finv[i-1]*inv[i]%modder;
      }
    }
    long nCk(int n,int k){
      if(n<k){return 0;}
      if(n<0||k<0){return 0;}
      return fac[n]*(finv[k]*finv[n-k]%modder)%modder;
    }
  }
  static <T extends Comparable<T>> int BSA(List<T> l,T target){
    return BSA(l,target,0,l.size(),(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSA(List<T> l,T target,Comparator<T> c){
    return BSA(l,target,0,l.size(),c);
  }
  static <T extends Comparable<T>> int BSA(List<T> l,T target,int left,int right){
    return BSA(l,target,left,right,(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSA(List<T> l,T target,int left,int right,Comparator<T> c){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      T gaze=l.get(lt+(rt-lt)/2);
      if(c.compare(gaze,target)<0){
        lt=lt+(rt-lt)/2+1;
      }else if(c.compare(gaze,target)>0){
        rt=lt+(rt-lt)/2-1;
      }else{
        return lt+(rt-lt)/2;
      }
    }
    return -1;
  }
  static <T extends Comparable<T>> int BSF(List<T> l,T target){
    return BSF(l,target,0,l.size(),(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSF(List<T> l,T target,Comparator<T> c){
    return BSF(l,target,0,l.size(),c);
  }
  static <T extends Comparable<T>> int BSF(List<T> l,T target,int left,int right){
    return BSF(l,target,left,right,(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSF(List<T> l,T target,int left,int right,Comparator<T> c){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      T gaze=l.get(lt+(rt-lt)/2);
      if(c.compare(gaze,target)<0){
        lt=lt+(rt-lt)/2+1;
      }else if(c.compare(gaze,target)>=0){
        rt=lt+(rt-lt)/2-1;
      }
    }
    return lt;
  }
  static <T extends Comparable<T>> int BSL(List<T> l,T target){
    return BSL(l,target,0,l.size(),(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSL(List<T> l,T target,Comparator<T> c){
    return BSL(l,target,0,l.size(),c);
  }
  static <T extends Comparable<T>> int BSL(List<T> l,T target,int left,int right){
    return BSL(l,target,left,right,(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSL(List<T> l,T target,int left,int right,Comparator<T> c){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      T gaze=l.get(lt+(rt-lt)/2);
      if(c.compare(gaze,target)<=0){
        lt=lt+(rt-lt)/2+1;
      }else if(c.compare(gaze,target)>0){
        rt=lt+(rt-lt)/2-1;
      }
    }
    return lt;
  }
  static <T extends Comparable<T>> int BSA(T[] a,T target){
    return BSA(a,target,0,a.length,(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSA(T[] a,T target,Comparator<T> c){
    return BSA(a,target,0,a.length,c);
  }
  static <T extends Comparable<T>> int BSA(T[] a,T target,int left,int right){
    return BSA(a,target,left,right,(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSA(T[] a,T target,int left,int right,Comparator<T> c){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      T gaze=a[lt+(rt-lt)/2];
      if(c.compare(gaze,target)<0){
        lt=lt+(rt-lt)/2+1;
      }else if(c.compare(gaze,target)>0){
        rt=lt+(rt-lt)/2-1;
      }else{
        return lt+(rt-lt)/2;
      }
    }
    return -1;
  }
  static <T extends Comparable<T>> int BSF(T[] a,T target){
    return BSF(a,target,0,a.length,(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSF(T[] a,T target,Comparator<T> c){
    return BSF(a,target,0,a.length,c);
  }
  static <T extends Comparable<T>> int BSF(T[] a,T target,int left,int right){
    return BSF(a,target,left,right,(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSF(T[] a,T target,int left,int right,Comparator<T> c){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      T gaze=a[lt+(rt-lt)/2];
      if(c.compare(gaze,target)<0){
        lt=lt+(rt-lt)/2+1;
      }else if(c.compare(gaze,target)>=0){
        rt=lt+(rt-lt)/2-1;
      }
    }
    return lt;
  }
  static <T extends Comparable<T>> int BSL(T[] a,T target){
    return BSL(a,target,0,a.length,(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSL(T[] a,T target,Comparator<T> c){
    return BSL(a,target,0,a.length,c);
  }
  static <T extends Comparable<T>> int BSL(T[] a,T target,int left,int right){
    return BSL(a,target,left,right,(s1,s2)->s1.compareTo(s2));
  }
  static <T> int BSL(T[] a,T target,int left,int right,Comparator<T> c){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      T gaze=a[lt+(rt-lt)/2];
      if(c.compare(gaze,target)<=0){
        lt=lt+(rt-lt)/2+1;
      }else if(c.compare(gaze,target)>0){
        rt=lt+(rt-lt)/2-1;
      }
    }
    return lt;
  }
  static int BSA(int[] a,int target){
    return BSA(a,target,0,a.length,true);
  }
  static int BSA(int[] a,int target, boolean syojun){
    return BSA(a,target,0,a.length,syojun);
  }
  static int BSA(int[] a,int target,int left,int right){
    return BSA(a,target,left,right,true);
  }
  static int BSA(int[] a,int target,int left,int right,boolean syojun){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      int gaze=a[lt+(rt-lt)/2];
      if((syojun&&gaze<target)||(!syojun&&gaze>target)){
        lt=lt+(rt-lt)/2+1;
      }else if((syojun&&gaze>target)||(!syojun&&gaze<target)){
        rt=lt+(rt-lt)/2-1;
      }else{
        return lt+(rt-lt)/2;
      }
    }
    return -1;
  }
  static int BSF(int[] a,int target){
    return BSF(a,target,0,a.length,true);
  }
  static int BSF(int[] a,int target,boolean syojun){
    return BSF(a,target,0,a.length,syojun);
  }
  static int BSF(int[] a,int target,int left,int right){
    return BSF(a,target,left,right,true);
  }
  static int BSF(int[] a,int target,int left,int right,boolean syojun){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      int gaze=a[lt+(rt-lt)/2];
      if((syojun&&gaze<target)||(!syojun&&gaze>target)){
        lt=lt+(rt-lt)/2+1;
      }else if((syojun&&gaze<=target)||(!syojun&&gaze>=target)){
        rt=lt+(rt-lt)/2-1;
      }
    }
    return lt;
  }
  static int BSL(int[] a,int target){
    return BSL(a,target,0,a.length,true);
  }
  static int BSL(int[] a,int target,boolean syojun){
    return BSL(a,target,0,a.length,syojun);
  }
  static int BSL(int[] a,int target,int left,int right){
    return BSL(a,target,left,right,true);
  }
  static int BSL(int[] a,int target,int left,int right,boolean syojun){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      int gaze=a[lt+(rt-lt)/2];
      if((syojun&&gaze<=target)||(!syojun&&gaze>=target)){
        lt=lt+(rt-lt)/2+1;
      }else if((syojun&&gaze>target)||(!syojun&&gaze<target)){
        rt=lt+(rt-lt)/2-1;
      }
    }
    return lt;
  }
  static int BSA(long[] a,long target){
    return BSA(a,target,0,a.length,true);
  }
  static int BSA(long[] a,long target, boolean syojun){
    return BSA(a,target,0,a.length,syojun);
  }
  static int BSA(long[] a,long target,int left,int right){
    return BSA(a,target,left,right,true);
  }
  static int BSA(long[] a,long target,int left,int right,boolean syojun){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      long gaze=a[lt+(rt-lt)/2];
      if((syojun&&gaze<target)||(!syojun&&gaze>target)){
        lt=lt+(rt-lt)/2+1;
      }else if((syojun&&gaze>target)||(!syojun&&gaze<target)){
        rt=lt+(rt-lt)/2-1;
      }else{
        return lt+(rt-lt)/2;
      }
    }
    return -1;
  }
  static int BSF(long[] a,long target){
    return BSF(a,target,0,a.length,true);
  }
  static int BSF(long[] a,long target,boolean syojun){
    return BSF(a,target,0,a.length,syojun);
  }
  static int BSF(long[] a,long target,int left,int right){
    return BSF(a,target,left,right,true);
  }
  static int BSF(long[] a,long target,int left,int right,boolean syojun){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      long gaze=a[lt+(rt-lt)/2];
      if((syojun&&gaze<target)||(!syojun&&gaze>target)){
        lt=lt+(rt-lt)/2+1;
      }else if((syojun&&gaze<=target)||(!syojun&&gaze>=target)){
        rt=lt+(rt-lt)/2-1;
      }
    }
    return lt;
  }
  static int BSL(long[] a,long target){
    return BSL(a,target,0,a.length,true);
  }
  static int BSL(long[] a,long target,boolean syojun){
    return BSL(a,target,0,a.length,syojun);
  }
  static int BSL(long[] a,long target,int left,int right){
    return BSL(a,target,left,right,true);
  }
  static int BSL(long[] a,long target,int left,int right,boolean syojun){
    int lt = left;
    int rt = right-1;
    while(lt<=rt){
      long gaze=a[lt+(rt-lt)/2];
      if((syojun&&gaze<=target)||(!syojun&&gaze>=target)){
        lt=lt+(rt-lt)/2+1;
      }else if((syojun&&gaze>target)||(!syojun&&gaze<target)){
        rt=lt+(rt-lt)/2-1;
      }
    }
    return lt;
  }
  static int kmp(String t,String p){
    int[] f=new int[p.length()+1];
    int i=0;
    int j=1;
    f[1]=0;
    while(j<p.length()){
      if(i==0||p.charAt(i-1)==p.charAt(j-1)){
        i++;
        j++;
        f[j]=i;
      }else{
        i=f[i];
      }
    }
    i=1;
    j=1;
    while(i<=p.length()&&j<=t.length()){
      if(i==0||p.charAt(i-1)==t.charAt(j-1)){
        i++;
        j++;
      }else{
        i=f[i];
      }
    }
    return i==(p.length()+1)?j-i:-1;
  }
  static String StSort(String s){
    StringBuilder sb = new StringBuilder(s);
    int lg = sb.length();
    int l;
    int r;
    int gaze;
    for(int i=1;i<lg;i++){
      l=0;
      r=i-1;
      while(l<=r){
        gaze=(l+r)/2;
        if(sb.charAt(gaze)<=sb.charAt(i)){
          l=gaze+1;
        }else if(sb.charAt(gaze)>sb.charAt(i)){
          r=gaze-1;
        }
      }
      sb.insert(l,sb.charAt(i));
      sb.deleteCharAt(i+1);
    }
    return sb.toString();
  }
  static class Xy{
    int x;
    int y;
    Xy(int x,int y){
      this.x=x;
      this.y=y;
    }
    public int manht(Xy o){
      return Math.abs(x-o.x)+Math.abs(y-o.y);
    }
    public String toString(){
      return "["+x+","+y+"]";
    }
    public double henkaku(){
      return Math.atan2(y,x);
    }
    public static int hencom(Xy s1,Xy s2){
      return (int)Math.signum(s1.henkaku()-s2.henkaku());
    }
    public boolean equals(Object o){
      return x==((Xy)o).x&&y==((Xy)o).y;
    }
  }
  static class UnFd{
    int n;
    int[] a;
    int forest;
    UnFd(int n){
      forest=this.n=n;
      a = new int[n];
      for(int i=0;i<n;i++){
        a[i] = i;
      }
    }
    boolean isRoot(int i){
      return a[i]==i;
    }
    int rootOf(int i){
      if(isRoot(i)){
        return i;
      }
      return a[i] = rootOf(a[i]);
    }
    boolean ud(int i,int j){
      return rootOf(i)==rootOf(j);
    }
    boolean marge(int i,int j){
      if(ud(i,j)){
        return false;
      }
      i=rootOf(i);
      j=rootOf(j);
      a[Integer.max(i,j)]=Integer.min(i,j);
      forest-=1;
      return true;
    }
    int[] roots(){
      int[] rs = new int[forest];
      int p=0;
      for(int i=0;i<n;i++){
        if(isRoot(i)){
          rs[p]=i;
          p++;
        }
      }
      return rs;
    }
  }
  static boolean next_permutation(int[] per){
    if(per.length<2){
      return false;
    }
    int i;
    for(i=per.length-1;i>0;i--){
      if(per[i-1]<per[i]){
        break;
      }
    }
    if(0<i){
      i--;
      int tmp;
      int j;
      for(j=per.length-1;j>i;j--){
        if(per[j]>per[i]){
          break;
        }
      }
      //swap(i,j)
      tmp=per[i];
      per[i]=per[j];
      per[j]=tmp;
      for(int k=i+1;k<(i+1+per.length)/2;k++){
        //swap(k,per.length-k+i)
        tmp=per[k];
        per[k]=per[per.length-k+i];
        per[per.length-k+i]=tmp;
      }
      return true;
    }
    int tmp;
    for(int k=0;k<per.length;k++){
      //swap(k,per.length-k-1)
      tmp=per[k];  
      per[k]=per[per.length-k-1];
      per[per.length-k-1]=tmp;
    }
    return false;
  }
  static boolean next_bits(boolean[] b){
    for(int i=0;i<b.length;i++){
      if(b[i]){
        b[i]=false;
      }else{
        b[i]=true;
        return true;
      }
    }
    return false;
  }
  static class Scnr{
    private final InputStream ins;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    Scnr(){
      this(System.in);
    }
    Scnr(InputStream in){
      ins = in;
    }
    private boolean hasNextByte(){
      if(ptr<buflen){
        return true;
      }else{
        ptr = 0;
        try{
          buflen = ins.read(buffer);
        }catch(IOException e){
          e.printStackTrace();
        }
        if(buflen<=0){
          return false;
        }
      }
      return true;
    }
    private int readByte(){
      if(hasNextByte()){
        return buffer[ptr++];
      }else{
        return -1;
      }
    }
    private static boolean isPrintableChar(int c){
      return 33<=c&&c<=126;
    }
    public boolean hasNext(){
      while(hasNextByte()&&!isPrintableChar(buffer[ptr])){
        ptr++;
      }
      return hasNextByte();
    }
    public String next(){
      return nextBuilder().toString();
    }
    public StringBuilder nextBuilder(){
      if(!hasNext()){
        throw new NoSuchElementException();
      }
      StringBuilder sb = new StringBuilder();
      int b = readByte();
      while(isPrintableChar(b)){
        sb.appendCodePoint(b);
        b = readByte();
      }
      return sb;
    }
    public double nextDouble(){
      return Double.parseDouble(next());
    }
    public long nextLong(){
      if(!hasNext()){
        throw new NoSuchElementException();
      }
      long n = 0;
      boolean minus = false;
      int b = readByte();
      if(b=='-'){
        minus=true;
        b=readByte();
      }
      if(b<'0'||'9'<b){
        throw new NumberFormatException();
      }
      while(true){
        if('0'<=b&&b<='9'){
          n*=10;
          n+=b-'0';
        }else if(b==-1||!isPrintableChar(b)){
          return minus?-n:n;
        }else{
          throw new NumberFormatException();
        }
        b=readByte();
      }
    }
    public int nextInt(){
      long nl=nextLong();
      if(nl<Integer.MIN_VALUE||Integer.MAX_VALUE<nl){
        throw new NumberFormatException();
      }
      return (int) nl;
    }
    public int[] nextAInt(int n){
      int[] a = new int[n];
      nextAInt(a,n);
      return a;
    }
    public void nextAInt(int[] a,int n){
      nextAInt(a,0,n);
    }
    public void nextAInt(int[] a,int off,int len){
      for(int i=off;i<off+len;i++){
        a[i] = nextInt();
      }
    }
    public long[] nextALong(int n){
      long[] a = new long[n];
      nextALong(a,n);
      return a;
    }
    public void nextALong(long[] a,int n){
      nextALong(a,0,n);
    }
    public void nextALong(long[] a,int off,int len){
      for(int i=off;i<off+len;i++){
        a[i] = nextLong();
      }
    }
    public double[] nextADouble(int n){
      double[] a = new double[n];
      nextADouble(a,n);
      return a;
    }
    public void nextADouble(double[] a,int n){
      nextADouble(a,0,n);
    }
    public void nextADouble(double[] a,int off,int len){
      for(int i=off;i<off+len;i++){
        a[i] = nextDouble();
      }
    }
    public List<Integer> nextLInt(int n){
      List<Integer> l = new ArrayList<>(n);
      for(int i=0;i<n;i++){
        l.add(sc.nextInt());
      }
      return l;
    }
    public List<Long> nextLLong(int n){
      List<Long> l = new ArrayList<>(n);
      for(int i=0;i<n;i++){
        l.add(sc.nextLong());
      }
      return l;
    }
    public List<Double> nextLDouble(int n){
      List<Double> l = new ArrayList<>(n);
      for(int i=0;i<n;i++){
        l.add(sc.nextDouble());
      }
      return l;
    }
  }
  
  static Scnr sc = new Scnr();
  static PrintWriter out = new PrintWriter(System.out);
  public static void main(String args[]){
    int n=sc.nextInt();
    int[] l=new int[n];
    int[] r=new int[n];
    int[] gomi=new int[n+n];
    for(int i=0;i<n;i++){
      int xx=sc.nextInt();
      int ll=sc.nextInt();
      l[i]=xx-ll+1;
      r[i]=xx+ll;
      gomi[2*i]=l[i];
      gomi[2*i+1]=r[i];
    }
    Map<Integer,Integer> zip=new HashMap<>();
    Arrays.sort(gomi);
    int mae=-2000000000;
    int zure=0;
    for(int i=0;i<n+n;i++){
      if(mae!=gomi[i]){
        zip.put(gomi[i],i-zure);
        mae=gomi[i];
      }else{
        zure++;
      }
    }
    Pair[] a=new Pair[n];
    for(int i=0;i<n;i++){
      a[i]=new Pair(zip.get(l[i]),zip.get(r[i]));
    }
    Arrays.sort(a,(s1,s2)->s1.l-s2.l);
//    out.println(Arrays.toString(a));
    NavigableSet<Integer> ns=new TreeSet<>();
    int cnt=0;
    for(int i=0;i<n;i++){
      Integer flag=ns.ceiling(a[i].f);
      if(flag==null||flag>a[i].l){
        cnt++;
        for(int j=a[i].f;j<=a[i].l;j++){
          ns.add(j);
        }
      }
    }
    out.print(cnt);
    out.flush();
  }
  static class Pair{
    int f;
    int l;
    Pair(int f,int l){
      this.f=f;
      this.l=l;
    }
    Pair copy(){
      return new Pair(f,l);
    }
    public String toString(){
      return String.valueOf(f)+","+String.valueOf(l);
    }
  }
}
