z = "abcdefghijklmnopqrstuvwxyz"
		
b = "".join(z[:n][::-1])
	
c = [b[0:i]+b[0:i+1][::-1] for i in range(n)]
    
d = ["-".join(i).center(n*4-3,"-") for i in c]

print("\n".join(d), "\n".join(d[::-1][1:]), sep="\n")