Solution.java

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Solution {
	public static boolean[][] box;
	public static List<Point> goList;
	
	public static void main(String[] args) {
		Scanner scan = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
		int T = scan.nextInt();
		int[] rList = new int[T];
		int[] cList = new int[T];
		for (int t = 0; t < T; t++) {
			rList[t] = scan.nextInt();
			cList[t] = scan.nextInt();
		}
		for (int t = 0; t < T; t++) {
		    
		    goList = new ArrayList<>();
			int R = rList[t];
			int C = cList[t];
			boolean isSwap = false;
			if (R > C) {
				isSwap = true;
				int temp;
				temp = R;
				R = C;
				C = temp;
			}
			boolean isPossible = isPossible(R, C) && isPossible(C, R);
			if (!isPossible) {
				System.out.println("Case #" + (t + 1) + ": IMPOSSIBLE");
				continue;
			} else {
				System.out.println("Case #" + (t + 1) + ": POSSIBLE");
			}
			
			box = new boolean[R + 1][C + 1];
			int i = 2, j = 3;
			
			while (i <= R) {
				while (j <= C) {
					checkNextRow(i, j);
					j++;
				}
				i++;
				j = 3;
			}
			goList.add(new Point(R, 1));
			goList.add(new Point(1, C));
			goList.add(new Point(R, 2));
			goList.add(new Point(1, C - 1));
			for (Point go : goList) {
				if (isSwap) {
					System.out.println(go.y + " " + go.x);
				} else {
					System.out.println(go.x + " " + go.y);
				}
				
			}
		}
		
	}
	
	public static boolean isPossible(int i, int j) {
		if (i < 2 || j < 2) {
			return false;
		}
		if (i == 2) {
			if (j < 5) {
				return false;
			}
		}
		if (i == 3) {
			if (j < 4) {
				return false;
			}
		}
		return true;
	}
	
	public static void checkNextRow(int i, int j) {
		if (i > 2 && j > 3 && !box[i][j] && !box[i - 1][i - 2]) {
			box[i][j] = true;
			box[i - 1][j - 2] = true;
		}
		goList.add(new Point(i, j));
		goList.add(new Point(i - 1, j - 2));
	}
	
	static class Point {
		int x, y;
		
		Point(int x, int y) {
			this.x = x;
			this.y = y;
		}
	}
}