#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++){
	    	if(i==1&&j==1||i==a&&j==b){
			
			   for(int j=1;j<=b;j++){
	    	       cout<<c;
			       if(j==b) cout<<endl;		
			   } 
			} else {
			        if(j==2){
			        cout<<c;
			        for(int j=2;j<=b-1;j++) cout<<" ";
			        cout<<c;
			        cout<<endl;
			        } 
				}
		   }
	   }
	} else{
		for(int i=1;i<=a;i++){
			for(int j=1;j<=b;j++){
				cout<<c; 
			}
			cout<<endl;
		}
	}
	return 0; 
}

各路大神求解