#include<bits/stdc++.h>
using namespace std;
int main() {
	int a,b,f;
	char c;
	cin>>a>>b>>c>>f;
	if(f != 0)
	{
		for(int i = 1;i <= a;i++)
		{
			for(int j = 1;j <= b;j++)
			{
				cout<<c;
			}
			cout<<endl;
		}
	}
	else
	{
		for(int i = 1;i <= a;i++)
		{
			for(int j = 1;j <= b;j++)
			{
				if(j == 1 || j == b)
					cout<<c;
				else
				{
					if(i == 1 || i == a)
						cout<<c;
					else
						cout<<' ';
				}
			}
			cout<<endl;
		}
	}
    return 0;
}