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

public class colorflip {
	
	Scanner in = new Scanner(System.in);
	boolean WHITE = true;
	boolean BLACK = false;
	double h;
	double v;
	double x;
	double y;
	
	public static void main(String[] args) {
		new colorflip().solve();
	}
	
	
	public void solve() {
		
		//in = new Scanner("81 32 0.333333333333 0.5\n6\n16 30\n16 25\n16 12.0001\n16 11.9999\n16 7.987654321\n16 7.0123456789\n10 10 0.123456789 0.987654321\n2\n0.432 0.9876\n9.432 0.9876\n0 0 0 0");
		
		// for each case
		int curr_case = 1;
		while(true) {
			
			// read dimensions
			String[] temp;
			try {
			
			temp = in.nextLine().split(" ");
			if(temp[0].equals("0")) break;
			
			double x_max = Double.parseDouble(temp[0]);
			double y_max = Double.parseDouble(temp[1]);
			h = Double.parseDouble(temp[2]);
			v = Double.parseDouble(temp[3]);
			
			int num_points = Integer.parseInt(in.nextLine());
			
			System.out.println("Case " + curr_case + ":");
			for(int i=0; i<num_points; i++) {
				temp = in.nextLine().split(" ");
				x = Double.parseDouble(temp[0]);
				y = y_max - Double.parseDouble(temp[1]);
				boolean answer = check(0,x_max,0,y_max,BLACK);
				if(answer == BLACK) System.out.println("black");
				else System.out.println("white");
			}
			
			} catch(Exception e) {
				break;
			}
			
			
			curr_case++;
		}
		
	}
	
	// return -1 for black, 1 for white
	public boolean check(double x_min, double x_max, double y_min, double y_max, boolean color) {
		
		double x_div = x_min+h*(x_max-x_min);
		double y_div = y_max-v*(y_max-y_min);

		//System.out.println("Checking " + x+","+y+" on "+x_min+" to "+x_max+", "+y_min+" to "+y_max+". Dividing at " + x_div +" and " +y_div +".");
		
		if(x < x_div) {
			if(y < y_div) {
				return color;
			}
			else return check(x_min,x_div,y_div,y_max,!color);
		}
		else if(y > y_div) {
			return color;
		}
		else return check(x_div,x_max,y_min,y_div,!color);
			
	}
	
}