#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;

int main()
{
    ll t,cas,i,j,k,l,m,n,a,b,c,d,e;
    cin>>t;
    for(cas=1;cas<=t;cas++)
    {
        cin>>n;
        vector<pair<ll,ll> >v;
        priority_queue<ll,vector<ll>,greater<ll> >q;

        for(i=0;i<n;i++)
        {
            cin>>a>>b;
            v.push_back(make_pair(a,b));
        }
        sort(v.begin(),v.end());
        for(i=0;i<v.size();i++)
        {
            q.push(v[i].second);
            if(v[i].first>q.top())
                q.pop();
        }
        cout<<"Case "<<cas<<": "<<q.size()<<endl;
    }
    return 0;
}