```cpp
#include<bits/stdc++.h>
struct px{
int a;
int b;
}x[2000000];
bool cmp(px x,px y){
return x.b<y.b;
}
using namespace std;
int main(){
int n,sum=1,mi;
cin>>n;
for(int i=1;i<=n;i++)
cin>>x[i].a>>x[i].b;
sort(x+1,x+n+1,cmp);
mi=x[1].b;
int j=1;
while(j<=n)
{
j++;
if(x[j].a>=mi) {
sum++;
mi=x[j].b;}
}
cout<<sum;
return 0;
}
```
by Felix66 @ 2024-02-23 20:14:37