#include <stdio.h>  

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