#include < iostream >
using   namespace  std;

struct  Node{
     int  l,r;
     int  cover;
};
struct  arr{
     int  x,y,z;
};
Node tree[ 100000 ];
int  color[ 10001 ];
int  l;
arr p[ 21000 ];
arr a[ 10100 ];
arr b[ 10100 ];
int  ans;
int  cmp( const   void *  no1, const   void *  no2){
    arr  * nox = (arr * )no1, * noy = (arr * )no2;
     return  nox -> x - noy -> x;
}
void  build( int  Num, int  l, int  r){
    tree[Num].l = l;
    tree[Num].r = r;
    tree[Num].cover = 0 ;
     if (l < r){
         int  mid = (l + r) >> 1 ;
        build(Num * 2 ,l,mid);
        build(Num * 2 + 1 ,mid + 1 ,r);
    }
}
void  insert( int  Num, int  l, int  r, int  col){
     if (l == tree[Num].l && r == tree[Num].r || tree[Num].cover == col){
        tree[Num].cover = col;
         return ;
    }
     if (tree[Num].cover > 0 ){
        tree[Num * 2 ].cover = tree[Num].cover;
        tree[Num * 2 + 1 ].cover = tree[Num].cover;
    }
    tree[Num].cover =- 1 ;
     int  mid = (tree[Num].l + tree[Num].r) >> 1 ;
     if (r <= mid) insert(Num * 2 ,l,r,col);
     else   if (l > mid) insert(Num * 2 + 1 ,l,r,col);
     else {
        insert(Num * 2 ,l,mid,col);
        insert(Num * 2 + 1 ,mid + 1 ,r,col);
    }
}
void  query( int  Num, int  l, int  r){
     if (tree[Num].cover > 0 ){
         if ( ! color[tree[Num].cover]){
            color[tree[Num].cover] = 1 ;
            ans ++ ;
        }
         return ;
    }
     else {
         int  mid = (l + r) >> 1 ;
        query(Num * 2 ,l,mid);
        query(Num * 2 + 1 ,mid + 1 ,r);
    }
}
int  main()
{
     int  t;
    scanf( " %d " , & t);
     while (t -- ){
         int  n;
        scanf( " %d " , & n);
        l = 0 ;
        p[l].x =- 1 ;
         for ( int  i = 1 ;i <= n; ++ i){
            scanf( " %d%d " , & a[i].x, & b[i].x);
            l ++ ;
            p[l].x = a[i].x;
            p[l].y = i;
            p[l].z = 0 ;
            l ++ ;
            p[l].x = b[i].x;
            p[l].y = i;
            p[l].z = 1 ;
        }
        qsort(p + 1 ,l, sizeof (arr),cmp);
         int  k = 0 ;
         for ( int  i = 1 ;i <= l; ++ i){
             if (p[i].x != p[i - 1 ].x){
                 k ++ ;
                 if ( ! p[i].z){
                    a[p[i].y].y = k;
                }
                 else  b[p[i].y].y = k;
            }
             else {
                 if ( ! p[i].z){
                    a[p[i].y].y = k;
                }
                 else  b[p[i].y].y = k;
            }
        }
        build( 1 , 1 ,k);
         for ( int  i = 1 ;i <= n; ++ i)
            insert( 1 ,a[i].y,b[i].y,i);
        memset(color, 0 , sizeof (color));
        ans = 0 ;
        query( 1 , 1 ,k);
        printf( " %d\n " ,ans);
    }
     return   0 ;
}