#include <bits/stdc++.h>
#define FIN "spectacole.in"
#define FOUT "spectacole.out"
#include <vector>
#include <algorithm>
 
typedef struct {
    int start,
        end;
} Interval;
 
bool cmp(Interval I1, Interval I2) {
     return I2.end > I1.end;
}
 
int main(int argc, char const *argv[]) {
 
    int n, x, y;
    Interval I;
    std::vector<Interval> spectacles;
 
    //freopen(FIN, "r", stdin);
    //freopen(FOUT, "w", stdout);
 
    std::cin>>n;
    for(int i = 0; i < n; ++i) {
        std::cin>>x>>y;
        I.start = x;
        I.end = y;
        spectacles.push_back(I);
    }
 
    //for(auto x: spectacles) {
 
      //std::cout<<x.start<<" "<<x.end<<std::endl;
    //}
 
    //std::cout<<std::endl;
 
    sort(spectacles.begin(), spectacles.end(), cmp);
 
    //for(std::vector<Interval>::iterator it = spectacles.begin(); it!=spectacles.end(); ++it)
 
        //std::cout<< (*it).start<<" "<<(*it).end<<"\n";
 
    int curr = spectacles[0].end;
 
    int i = 1;
 
    int count = 1;
 
    while (i < n){
 
        if(spectacles[i].start >= curr) {
 
            curr = spectacles[i].end;
 
            count++;
        }
      i++;}
 
    std::cout<<count;
 
  return 0;
}
 

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