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