w,h,c = input().split()

if c == "B":
    even = "W"
else:
    even = "B"

array = [["" for i in range(int(w))]for j in range(int(h))]

for line in array:
    for i in range(len(line)):
        if i%2==0:
            line[i]=c
        else:
            line[i]=even
            
for line in array:
    for letter in line:
        print(letter,end="")
    print()
print()