import java.util.*;
import java.io.*;

class Main{

    static int n;

    static double[] y;

    static Node[] tr;

    static BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    static BufferedWriter out = new BufferedWriter(new OutputStreamWriter(System.out));

    static class Segment implements Comparable<Segment>{

        double x, y1, y2; 
        int k;

        public Segment(double x, double y1, double y2, int k){
            this.x = x;
            this.y1 = y1;
            this.y2 = y2;
            this.k = k;
        }

        @Override
        public int compareTo(Segment o){
            if(this.x==o.x) return 0;
            return this.x>o.x? 1:-1;
        }
    }

    static class Node{
        int l, r, cnt;
        double len;
        public Node(int l, int r, int cnt, double len){
            this.l = l;
            this.r = r;
            this.cnt = cnt;
            this.len = len;
        }
    }

    static void build(int u, int l, int r){
        tr[u] = new Node(l, r, 0, 0);
        if(l!=r){
            int mid = l + r >> 1;
            build(u<<1, l, mid);
            build(u<<1|1, mid+1, r);
        }
    }

    static void pushup(int u){
        if(tr[u].cnt>0) tr[u].len = y[tr[u].r+1]- y[tr[u].l];
        else if(tr[u].l!=tr[u].r)
            tr[u].len = tr[u<<1].len + tr[u<<1|1].len;
        else tr[u].len = 0;
    }


    static void modify(int u, int l, int r, int k){
        if(tr[u].l>=l&&tr[u].r<=r)
            tr[u].cnt += k;
        else{
            int mid = tr[u].l + tr[u].r >> 1;
            if(l<=mid) modify(u<<1, l, r, k);
            if(r>mid) modify(u<<1|1, l, r, k);
        }
        pushup(u);
    }

    static int unique(double[] a){
        int offset = 0;
        for(int i=1; i<a.length; i++){
            if(a[i]==a[i-1]){
                offset++;
                continue;
            }
            a[i-offset] = a[i];
        }
        return a.length - offset;
    }

    public static void main(String[] args) throws Exception{
        int T = 1;
        while(true){
            String[]s = in.readLine().split(" ");
            n = Integer.valueOf(s[0]);
            if(n==0) break;
            Segment[] segs = new Segment[2*n];
            tr = new Node[8*n];
            y = new double[2*n];
            int i = 0, j = 0;
            double x1, y1, x2, y2;
            while(n-->0){
                s = in.readLine().split(" ");
                x1 = Double.valueOf(s[0]);
                y1 = Double.valueOf(s[1]);
                x2 = Double.valueOf(s[2]);
                y2 = Double.valueOf(s[3]);
                segs[j++] = new Segment(x1, y1, y2, 1);
                segs[j++] = new Segment(x2, y1, y2, -1);
                y[i++] = y1;
                y[i++] = y2;
            }

            Arrays.sort(segs);
            Arrays.sort(y);

            int ll = unique(y);

            HashMap<Double, Integer> map = new HashMap<>();
            for(j=0; j<ll; j++) map.put(y[j], j);
            build(1, 0, map.size()-2);
            double res = 0;
            for(i=0; i<segs.length; i++){
                if(i>0) res += (segs[i].x - segs[i-1].x) * tr[1].len;
                modify(1, map.get(segs[i].y1), map.get(segs[i].y2)-1, segs[i].k);
            }
            map.clear();
            out.write("Test case #"+ T++ +"\n");
            out.write("Total explored area: "+ String.format("%.2f", res)+"\n\n");

        }
        out.flush();
    }
}