#include <iostream>
using namespace std;

int main()
{
    int a, b, f;
    char c;
    cin >> a >> b >> c >> f;
    if (f == 1)
    {
    	for (int i = 1; i <= a; i++)
    	{
    		for (int j = 1; j <= b; j++)
    		{
    			cout << c;
			}
			cout << endl;
		}
		return 0;
	}
    for (int i = 1; i <= b; i++)
    {
    	cout << c;
	}
	cout << endl;
	for (int i = 1; i <= a - 2; i++)
	{
		cout << c;
		for (int j = 1; j <= b - 2; j++)
		{
			cout << " ";
		}
		cout << c << endl;
	}
	for (int i = 1; i <= b; i++)
    {
    	cout << c;
	}
	return 0;
}