#include <bits/stdc++.h>
using namespace std ;

typedef long long ll ;
long long t , cs , n , a[1000] , b[10000] ;


int main(){

    cin>>t;
    while(cs<t){
        cs++;
        scanf("%lld",&n);
        for(ll  i = 0 ; i < n ; i++)scanf("%lld %lld",&a[i],&b[i]);

        ll ans = 0 ;
        ll l = a[0] , q = b[0] , k = 1 , in = 0 ;
        for(ll i = 1 ; i <= n ; i++){
           // cout << i << " " << l << " " << q << " " << k << " " << in << endl ;
            if(i==n){
                if(k>=3)ans++;
            }
            else{
                 if(a[i]!=l){
                     if(k>=3)ans++;
                     l = a[i] , q = b[i] , k = 1 , in = 0;
                 }
                 else if(k == 1 ){
                    k++ ; l = a[i]  , in = b[i] - q , q = b[i];
                 }
                 else if(in != b[i]-q){
                     if(k>=3)ans++;
                     l = a[i] , q = b[i] , k = 1, in = 0 ;
                 }
                 else {
                    k++ ; l = a[i]  , in = b[i] - q , q = b[i];
                 }

            }

        }
        printf("Case %lld: %lld\n",cs,ans);
    }
return 0 ;
}