#define filer() freopen("in.txt","r",stdin)
#define filew() freopen("out.txt","w",stdout)
#define SET(a, x) memset((a), (x), sizeof(a))
#define i64 long long
#include<iostream>
#include<stdio.h>
#include<string.h>
#include<math.h>
#include<algorithm>
#include<queue>
#include<stack>
#include<vector>
#include <map>
#define INF 1<<29

using namespace std;

int vst[10000010];

vector<int>P;

struct NODE
{
    int l,r,order;
};

int M[1048576];

int LZY[1048576];

int TRUE;

priority_queue<NODE>PQ;

bool operator<(NODE a ,NODE b)
{
    return a.order<b.order;
}

bool query(int b,int e,int lft,int rite,int i)
{
    if(LZY[i]==1)
    {

        M[i]=rite-lft+1;
    }

    if(lft>e || rite<b)return 0;


    if(lft>=b && rite<=e)
    {
        if(M[i]==(rite-lft+1))return 0;
        return 1;
    }
    if(LZY[i]==1){LZY[i]=1;LZY[2*i]=1;LZY[2*i+1]=1;}
    bool x=query(b,e,lft,(lft+rite)/2,2*i);
    bool y=query(b,e,(lft+rite)/2+1,rite,2*i+1);

    return (x || y);
}

void update(int b,int e,int lft,int rite,int i)
{
    if(lft>e || rite<b)return ;

    if(lft>=b && rite<=e)
    {
        M[i]=rite-lft+1;
        LZY[i]=1;
        return ;
    }

    update(b,e,lft,(lft+rite)/2,2*i);
    update(b,e,(lft+rite)/2+1,rite,2*i+1);

    M[i]=M[2*i]+M[2*i+1];

}

int search(int x,int sz)
{
    int lo,hi,mid;

    lo=0;hi=sz-1;
    while(lo<=hi)
    {
        mid=(lo+hi)/2;

        if(P[mid]==x)return mid;
        else if(P[mid]<x)lo=mid+1;
        else hi=mid-1;
    }
}

int main()
{
    //filer();
    int T,cas=0,n,i,cov,ans;
    NODE S;
    scanf("%d",&T);
    while(T--)
    {
        TRUE++;
        ans=0;

        scanf("%d",&n);
        for(i=0;i<n;i++)
        {
            scanf("%d%d",&S.l,&S.r);
            S.order=i;
            if(vst[S.l]!=TRUE){P.push_back(S.l);vst[S.l]=TRUE;}
            if(vst[S.r]!=TRUE){P.push_back(S.r);vst[S.r]=TRUE;}
            PQ.push(S);
        }
        sort(P.begin(),P.end());
        while(!PQ.empty())
        {
            S=PQ.top();
            PQ.pop();

            int sz=P.size();
            int x=search(S.l,sz);
            int y=search(S.r,sz);

            if(query(x,y,0,sz-1,1))
            {
                ans++;
                update(x,y,0,sz-1,1);
            }
        }
        printf("%d\n",ans);
        if(T){SET(M,0);SET(LZY,0);}
    }
    return 0;
}