C++ :

#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
struct fun
{
    int length;
    int weight;
} s[5010];
int cmp(fun a,fun b)
{
    if(a.length!=b.length)
        return a.length<b.length;
    else
        return a.weight<b.weight;
}
int main()
{
    int n,m,count,end,j;
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    cin>>n;
    while(n--)
    {
        count=0;
        cin>>m;
        for(int i=0; i<m; i++)
            cin>>s[i].length>>s[i].weight;
        sort(s,s+m,cmp);
        for(int i=0; i<m; i++)
        {
            end=s[i].weight;
            if(s[i].weight!=0)
            {
                for(j=i+1; j<m; j++)
                    if(s[j].weight>=end)
                    {
                        end=s[j].weight;
                        s[j].weight=0;
                    }
                count++;
            }

        }
        cout<<count<<endl;
    }
}