import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       int gao = sc.nextInt();
       int kuan = sc.nextInt();
       char fu = sc.next().charAt(0);
       int a = sc.nextInt();
       if (a==0){

               for (int j = 0; j < gao; j++) {
                   if (j==0||j==gao-1){
                       for (int k = 0; k < kuan; k++) {
                           System.out.print(fu);
                       }
                       System.out.println("");
                   }else {
                       System.out.print(fu);
                       for (int k = 0; k < kuan-2; k++) {
                           System.out.print(" ");
                       }
                       System.out.print(fu);
                       System.out.println("");

                   }

           }
       }else {
           for (int i = 0; i < gao; i++) {
               for (int j = 0; j < kuan; j++) {
                   System.out.print(fu);
               }
               System.out.println("");
           }
       }
    }
}