#include <stdio.h>

#include <memory.h>

#include <math.h>

#include <string>

#include <vector>

#include <set>

#include <stack>

#include <queue>

#include <algorithm>

#include <map>

#define I scanf

#define OL puts

#define O printf

#define F(a,b,c) for(a=b;a<c;a++)

#define FF(a,b) for(a=0;a<b;a++)

#define FG(a,b) for(a=b-1;a>=0;a--)

#define LEN 1010

#define MAX 1<<30

#define V vector<int>

using namespace std;

int dp[LEN];

int r[LEN];

int c[LEN];

int N,ans=;

bool Greater(int a,int b){

    if((r[a]>r[b]&&c[a]>c[b])

    ||(c[a]>r[b]&&r[a]>c[b])) return ;

    return ;

}

int DP(int x){

    if(dp[x]>) return dp[x];

    dp[x]=;

    int i;

    FF(i,N){

        if(Greater(x,i)){    //顶点x到顶点y连通

            dp[x]=max(dp[x],+DP(i));

        }

    }

    ans=max(ans,dp[x]);

    return dp[x];

}

int main(){

//    freopen("矩形嵌套.txt","r",stdin);

    int i,j,T;

    I("%d",&T);

    while(T--){

        ans=;

        memset(dp,,sizeof dp);

        I("%d",&N);

        FF(i,N){

            I("%d%d",&r[i],&c[i]);

        }

        FF(i,N) DP(i);

        O("%d\n",ans);

    }

    return ;

}