a,b,c,d=input().split() a=int(a) b=int(b) d=int(d) if d!=0: for i in range(0,a): for j in range(0,b): print(c,end="") print(end="\n") if d==0: for i in range(0,a): for j in range(0,b): if i==0 or i==a-1: print(c, end="") elif j==0 or j==b-1 : print(c,end="") else : print(end=" ") print(end="\n")