#include? < stdio.h >
#include? < stdlib.h >
#include? < string .h >

#define ?N?5001

struct ?Node
{
???? int ?length;
???? int ?weight;
};

int ?n;
Node?d[N];
bool ?visite[N];

int ?cmp(? const ? void * ?a,? const ? void * ?b?)
{
????Node * ?ta = ?(Node * )a;
????Node * ?tb = ?(Node * )b;
????
???? if (?ta -> length == ?tb -> length?)? return ?ta -> weight - ?tb -> weight;
????
???? return ?ta -> length - ?tb -> length;
}

int ?main()
{
???? int ?test;
????scanf( " %d " ,? & test);
????
???? while (?test -- ?)
????{
????????scanf( " %d " ,? & n?);
???????? for (? int ?i = ? 0 ;?i < ?n;? ++ i?)
????????scanf( " %d%d " ,????? & d[i].length,? & d[i].weight?);
????????
????????qsort(?d,?n,? sizeof (d[ 0 ]),?cmp?);
????????memset(?visite,? false ,? sizeof (visite)?);
????
???????? int ?b = ?d[ 0 ].weight;
???????? int ?num = ? 0 ;
???????? int ?k = ? 0 ;
????????
???????? while (? true ?)
????????{
???????????? bool ?ok = ? false ;
????????????
???????????? if (?k == ? - 1 ?)? break ;
????????????b = ?d[k].weight;???num ++ ;
????????????
???????????? int ?be = ?k;??k = ? - 1 ;
????????????
???????????? for (? int ?i = ?be;?i < ?n;? ++ i?)
????????????{
???????????????? if (?d[i].weight >= ?b? && ? ! visite[i]?)
????????????????{
????????????????????visite[i] = ? true ;
????????????????????b = ?d[i].weight;
????????????????}
???????????????? else ? if (? ! ok? && ? ! visite[i]?)???{???k = ?i;??ok = ? true ;??}
????????????}?
????????}
????????
????????printf( " %d\n " ,?num?);
????}
????
???? return ? 0 ;
}