import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		char c = sc.next().charAt(0);
		int f = sc.nextInt();
		for (int i = 1; i <= a; i++) {
			for (int j = 1; j <= b; j++) {
				if(f == 0) {
					if(i != 1 && i != a && j != 1 && j !=b) {
						System.out.print(' ');
					}
					else {
						System.out.print(c);
					}
				}
				else{
				    System.out.print(c);
				}
			}
			System.out.println();
		}
		sc.close();

	}

}