/*
 * Atlantis : Problem A from the Mid-Central European Regional Contest 2000
 * of the ACM Programming contest.
 *
 * Given a set of rectangles with vertices of real (double) coordinates,
 * determine the total area the set of rectangles mutually cover.
 *
 * Parke Godfrey
 * 18 September 2008
 */

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

/*
 * Rectangle : Holds a rectangle.
 */

class Rectangle implements Comparable {
    public final double xLow;
    public final double yLow;
    public final double xHigh;
    public final double yHigh;

    public final double area;

    public Rectangle(double xL, double yL, double xH, double yH) {
        xLow  = xL;
        yLow  = yL;
        xHigh = xH;
        yHigh = yH;

        area = (xHigh - xLow) * (yHigh - yLow);
    }

    // Whether the other rectangle overlaps with or touches this one.
    public boolean touches(Rectangle other) {
        if ( 
                ((this.xLow <= other.xLow)  && (this.xHigh >= other.xLow)  &&
                 (this.yLow <= other.yLow)  && (this.yHigh >= other.yLow))
            ||
                ((this.xLow <= other.xLow)  && (this.xHigh >= other.xLow)  &&
                 (this.yLow <= other.yHigh) && (this.yHigh >= other.yHigh))
            ||
                ((this.xLow <= other.xHigh) && (this.xHigh >= other.xHigh) &&
                 (this.yLow <= other.yLow)  && (this.yHigh >= other.yLow))
            ||
                ((this.xLow <= other.xHigh) && (this.xHigh >= other.xHigh) &&
                 (this.yLow <= other.yHigh) && (this.yHigh >= other.yHigh))
           ) {
           return true;
        } else {
           return false;
        }
    }

    public int compareTo(Object obj) {
        Rectangle other = (Rectangle) obj;
        if (this.area > other.area) {
            return -1;
        } else if (this.area < other.area) {
            return 1;
        } else {
            return 0;
        }
    }
}

public class RectCover {
    private static Stack<Rectangle> frag = new Stack<Rectangle>();

    private static void fragment(Rectangle base) {
        if (!frag.empty()) {
            Rectangle box = frag.pop(); // Take a box to check.
            fragment(base); // Handle rest of stack.

            // Check if the boxes do not overlap or even touch.
            if (!base.touches(box)) {
               frag.push(box); // Put it back.
               return;
            }

            // We overlap (or touch).  So add any pieces that result
            // from trimming base away from box.
            if (box.yLow < base.yLow) {
                Rectangle piece = new Rectangle(
                        box.xLow,
                        box.yLow,
                        box.xHigh,
                        base.yLow
                    );
                frag.push(piece);
            }
            if (box.yHigh > base.yHigh) {
                Rectangle piece = new Rectangle(
                        box.xLow,
                        base.yHigh,
                        box.xHigh,
                        box.yHigh
                    );
                frag.push(piece);
            }
            if (box.xLow < base.xLow) {
                Rectangle piece = new Rectangle(
                        box.xLow,
                        Math.max(box.yLow, base.yLow),
                        base.xLow,
                        Math.min(box.yHigh, base.yHigh)
                    );
                frag.push(piece);
            }
            if (box.xHigh > base.xHigh) {
                Rectangle piece = new Rectangle(
                        base.xHigh,
                        Math.max(box.yLow, base.yLow),
                        box.xHigh,
                        Math.min(box.yHigh, base.yHigh)
                    );
                frag.push(piece);
            }

            // If no pieces, the box was contained by the base rectangle.
        }
    }

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        PrintStream output = System.out;

        int trial = 0;
        int rectNum = input.nextInt();
        while (rectNum > 0) {
            trial++;

            // Read in the list of rectangles for this trial.
            Rectangle[] recArray = new Rectangle[rectNum];
            for (int r = 0; r < rectNum; r++) {
                // Grab the next rectangle from input.
                recArray[r] =
                    new Rectangle(
                            input.nextDouble(),
                            input.nextDouble(),
                            input.nextDouble(),
                            input.nextDouble()
                        );
            }
            Arrays.sort(recArray); // Now in descending order by size.

            double area = 0;
            // Keep a list of rectangles we need to clip against.
            Rectangle[] recCheck = new Rectangle[rectNum];
            int checkEnd = 0;
            // Walk through the rectangles and clip each to find the area
            // each contributes to the overall area covered.
            for (int r = 0; r < rectNum; r++) {
                frag.push(recArray[r]);
                for (int c = 0; c < checkEnd; c++) {
                    fragment(recCheck[c]);
                    if (frag.empty()) break;
                }

                if (!frag.empty())
                    recCheck[checkEnd++] = recArray[r];
                while (!frag.empty())
                    area += (frag.pop()).area;
            }

            // Print out the area for this trial.
            output.print("Test case #");
            output.print(trial);
            output.println("");
            output.print("Total explored area: ");
            output.printf("%.2f\n", area);
            output.println("");

            rectNum = input.nextInt();
        }
    }
}