w,h,c = input().split()
if c == "B":
    even = "W"
else:
    even = "B"
    
for i in range(int(h)):
    for j in range(int(w)):
        if j%2==0 and i%2==0 or j%2!=0 and i%2!=0:
            print(c,end="")
        elif j%2!=0 and i%2==0 or j%2==0 and i%2!=0:
            print(even,end="")
    print()