#include <stdio.h>
long a[100002],b[100002],c[100002],d[100002],i,n;
int main(){
	FILE *f,*g;
	f=fopen("heavymetal.in","r");
	g=fopen("heavymetal.out","w");
	fscanf(f,"%ld",&n);
	for(i=1;i<=n;i++)
		fscanf(f,"%ld%ld",&a[i],&b[i]);
	c[1]=0;
	for(i=2;i<=n;i++)
		if(a[i]<=b[i-1]) c[i]=c[i-1];
		else c[i]=c[i-1]+1;
	fclose(f);
	fclose(g);
	return 0;
}