#include<stdio.h>
#include<stdlib.h>
#include<memory.h>
int flag[5002];
struct in
{
	int x;
	int y;
}s[5002];
int cmp(const void *a,const void *b)
{
	struct in *c=(struct in *)a;
	struct in *d=(struct in *)b;
	if(c->x!=d->x)
		return c->x-d->x;
	else
		return d->y-c->y;
}
int main()
{
	int t,n,minmin,i,j,temp;
	scanf("%d",&t);
	while(t--)
	{
		scanf("%d",&n);
		minmin=0;
		for(i=0;i<n;i++)
			scanf("%d%d",&s[i].x,&s[i].y);
		qsort(s,n,sizeof(s[0]),cmp);
		memset(flag,1,sizeof(flag));
		for(i=0;i<n;i++)
		{
			if(flag[i])
			{
				minmin++;
				temp=s[i].y;
				for(j=i+1;j<n;j++)
				{
					if(flag[j]&&s[j].y>=temp)
					{
						flag[j]=0;
						temp=s[j].y;
					}
				}
			}
		}
		printf("%d\n",minmin);
	}
	return 0;
}