#include <bits/stdc++.h>
#define maxn 10005
struct Line
{
    double x,y_down,y_up;
    int flag;
    bool operator <(const Line &a)
    {
        return x<a.x;
    }
}line[maxn];
struct Tree
{
    double y_down,y_up;
    double x;
    int cover;//用以表示加进线段树的线段次数
    bool flag;
}tree[maxn*100];
int n;
double xx1,yy1,xx2,yy2;
int cnt=0;
double y[2*maxn];
void build(int l,int r,int rt)
{
    tree[rt].x=-1;
    tree[rt].cover=0;
    tree[rt].y_down=y[l];
    tree[rt].y_up=y[r];
    tree[rt].flag=false;
    if(l+1==r)
    {
        tree[rt].flag=true;
        return;
    }
    int mid=(l+r)>>1;
    build(l,mid,rt*2);
    build(mid,r,rt*2+1);
}
double insert_tree(int rt,double x,double l,double r,int flag)//flag表示是左边还是右边
{
    if(r<=tree[rt].y_down||l>=tree[rt].y_up)
    {
        return 0;
    }
    if(tree[rt].flag)
    {
        if(tree[rt].cover>0)
        {
            double temp_x=tree[rt].x;
            double ans=(x-temp_x)*(tree[rt].y_up-tree[rt].y_down);
            tree[rt].x=x;
            tree[rt].cover+=flag;
            return ans;
        }
        else
        {
            tree[rt].cover+=flag;
            tree[rt].x=x;
            return 0;
        }
    }
    double ans1,ans2;
    ans1=insert_tree(rt*2,x,l,r,flag);
    ans2=insert_tree(rt*2+1,x,l,r,flag);
    return ans1+ans2;
}
int main()
{
    int n,i;
    int cas=0;
    while(std::cin>>n&&n)
    {
        cnt=1;
        for(int i=1;i<=n;i++)
        {
            scanf("%lf%lf%lf%lf",&xx1,&yy1,&xx2,&yy2);
            y[cnt]=yy1;
            line[cnt].x=xx1;
            line[cnt].y_down=yy1;
            line[cnt].y_up=yy2;
            line[cnt].flag=1;
            cnt++;
            y[cnt]=yy2;
            line[cnt].x=xx2;
            line[cnt].y_down=yy1;
            line[cnt].y_up=yy2;
            line[cnt].flag=-1;
            cnt++;
        }
        std::sort(y+1,y+cnt);
        std::sort(line+1,line+cnt);
        build(1,cnt-1,1);
        double ans=0;
        for(int i=1;i<cnt;i++)
        {    //std::cout<<"gg"<<std::endl;
            ans+=insert_tree(1,line[i].x,line[i].y_down,line[i].y_up,line[i].flag);
        }
         printf("Test case #%d\nTotal explored area: %.2f\n\n", ++cas, ans);
    }
    return 0;
}