#include<bits/stdc++.h>
using namespace std;
typedef long long INT;
const int maxn=1e5+200;
int n;
const int Mv=1e6;
const double eps=1e-2;
struct Spirit{
    double x;
    double w;
}spirits[5*maxn];
double Abs(double xx){
    return xx>0?xx:-xx;
}
double Pow(double x,int nn){
    double ret=1.0;
    for(int i=1;i<=nn;i++)
        ret*=x;
    return ret;
}
double cal(double xx){
    double sum=0;
    for(int i=1;i<=n;i++){
        sum+=Pow(Abs(spirits[i].x-xx),3)*spirits[i].w;
    }
    return sum;
}
double three_div(double L,double R){    //三分求最值
    double mid=(L+R)/2,mid_L=(L+mid)/2;
    while(Abs(cal(mid)-cal(mid_L))>eps){ //条件应该视情况而定
        mid=(R+L)/2.0;
        mid_L=(L+mid)/2.0;
        if(cal(mid)>cal(mid_L)){
            R=mid;
        }else{
            L=mid_L;
        }
    }
    return mid; //得到最值的坐标位置
}
int main(){
    int t,cnt=0;
    scanf("%d",&t);
    double min_v=Mv*(-1.0),max_v=Mv*1.0;
    while(t--){
        scanf("%d",&n);
        for(int i=1;i<=n;i++){
            scanf("%lf%lf",&spirits[i].x,&spirits[i].w);
        }
        double xx=three_div(min_v,max_v);
        printf("Case #%d: %lld\n",++cnt,(INT)(cal(xx)+0.5));
    }
    return 0;
}