#include <stdio.h>
#include <stdlib.h>
 const int N=50004;
 struct interval()
 {
	 int a,b;
 };
int n;
int e[50004];
interval e[N];
void citire()
{
	fscanf(f1,"%d",&n);
	for(int i=1;i<=n;i++)
	{
		fscanf(f1,"%d %d",&e[i].a,&e[i].b);
	}
}
int compar(const void *p,const void *q)
{
	interval x=*(interval*)p,y=*(interval*)q;
	if(x.b<y.b)
		return -1;
	if(x.b>y.b)
		return 1;
	return 0;
}
void calcul()
{
	int i,dr=e[1].b,nr=1;
	for(i=1;i<=n;++i)
	{
		if(e[i].a>=dr)
		{
			++nr;
			dr=e[i].b;
		}
		return nr;
	}
}
	
 
int main()
{
	FILE *f1,*f2;
	f1=fopen("int.in","r");
	f2=fopen("int.out","w");
	citire();
	qsort(e+1,n,sizeof(v[0]),compar);
	fprintf(f2,"%d\n",calcul());
	fclose(f1);
	fclose(f2);
	
	
	
	return 0;
}