#include <stdio.h>
int main(){
	int i,j,a,b,f;
	char c;
	scanf("%d %d %c %d",&a,&b,&c,&f);
	for (i=1;i<=b;i++){
		printf("%c",c);
	}
	printf("\n");
	for (i=1;i<=a-2;i++){
		if (f == 0){
			printf("%c",c);
			for (j=1;j<=b-2;j++){
				printf(" ");
			}
			printf("%c",c);
			printf("\n");
		}else{
			for (j=1;j<=b;j++){
				printf("%c",c);
			}
			printf("\n");
		}
	}
	for (i=1;i<=b;i++){
		printf("%c",c);
	}
	return 0;
}