#include<iostream>
#include<cstring>
#include<algorithm>
#include<cstdio>
#include<vector>
#include<sstream>
#include<string>
#include<climits>
#include<stack>
#include<set>
#include<bitset>
#include<cmath>
#include<deque>
#include<map>
#include<queue>
#define iinf 2000000000
#define linf 1000000000000000000LL
#define dinf 1e200
#define eps 1e-5
#define all(v) (v).begin(),(v).end()
#define sz(x)  x.size()
#define pb push_back
#define mp make_pair
#define lng long long
#define sqr(a) ((a)*(a))
#define pii pair<int,int>
#define pll pair<lng,lng>
#define pss pair<string,string>
#define pdd pair<double,double>
#define X first
#define Y second
#define pi 3.14159265359
#define ff(i,xi,n) for(int i=xi;i<=(int)(n);++i)
#define ffd(i,xi,n) for(int i=xi;i>=(int)(n);--i)
#define ffl(i,r) for(int i=head[r];i!=-1;i=edge[i].next)
#define cc(i,j) memset(i,j,sizeof(i))
#define two(x)			((lng)1<<(x))
#define N 11111
#define M 1000000
#define lson l , mid , rt << 1
#define rson mid + 1 , r , rt << 1 | 1
#define Mod  n
#define Pmod(x) (x%Mod+Mod)%Mod
using namespace std;
typedef vector<int>  vi;
typedef vector<string>  vs;
typedef unsigned int uint;
typedef unsigned lng ulng;
template<class T> inline void checkmax(T &x,T y){if(x<y) x=y;}
template<class T> inline void checkmin(T &x,T y){if(x>y) x=y;}
template<class T> inline T Min(T x,T y){return (x>y?y:x);}
template<class T> inline T Max(T x,T y){return (x<y?y:x);}
template<class T> T gcd(T a,T  b){return (a%b)==0?b:gcd(b,a%b);}
template<class T> T lcm(T a,T b){return a*b/gcd(a,b);}
template<class T> T Abs(T a){return a>0?a:(-a);}
template<class T> inline T lowbit(T n){return (n^(n-1))&n;}
template<class T> inline int countbit(T n){return (n==0)?0:(1+countbit(n&(n-1)));}
template<class T> inline bool isPrimeNumber(T n)
{if(n<=1)return false;for (T i=2;i*i<=n;i++) if (n%i==0) return false;return true;}
struct ps
{
    int id,val;
}s[2*N];
int le[N],ri[N],clo[N<<4],n,ncase,y,cnt;
bool in[N];
bool cmp(ps p,ps q)
{
    return p.val<q.val;
}
inline void pushdown(int rt)
{
    if(clo[rt])
    {
        clo[rt<<1]=clo[rt<<1|1]=clo[rt];
        clo[rt]=0;
    }
}
void update(int L,int R,int color,int l,int r,int rt)
{
    if(L<=l&&r<=R)
    {
        clo[rt]=color;
        return ;
    }
    int mid=(l+r)>>1;
    pushdown(rt);
    if(L<=mid)  update(L,R,color,lson);
    if(R>mid) update(L,R,color,rson);
}
void query(int l,int r,int rt)
{
    if(clo[rt])
    {
        if(!in[clo[rt]])
        in[clo[rt]]=1,cnt++;
        return ;
    }
    int mid=(l+r)>>1;
    if (l==r) return ;
    query(lson);
    query(rson);
}
int main()
{
   scanf("%d",&ncase);
   while(ncase--)
   {
       scanf("%d",&n);
       y=0;
       ff(i,1,n)
       {
           scanf("%d",&s[i*2-1].val);
           s[i*2-1].id=i;
           scanf("%d",&s[i*2].val);
           s[i*2].id=i;
       }
       sort(s+1,s+2*n+1,cmp);
       s[0].val=-iinf;
       cc(le,0);
       ff(i,1,2*n)
       {
           if(s[i].val==s[i-1].val)
           {
               if(le[s[i].id])
               ri[s[i].id]=y;
               else
               le[s[i].id]=y;
           }
           else
           if(i>=2&&s[i].val>s[i-1].val+1)
           {
               y+=2;
                if(le[s[i].id])
               ri[s[i].id]=y;
               else
               le[s[i].id]=y;
           }
           else
           { y+=1;
                if(le[s[i].id])
               ri[s[i].id]=y;
               else
               le[s[i].id]=y;
           }
       }
       cc(clo,0);
       cc(in,0);
       cnt=0;
       ff(i,1,n)
       update(le[i],ri[i],i,1,y,1);
       query(1,y,1);
       printf("%d\n",cnt);
   }
    return 0;
}