W,H,C = input().split()
D = 'W' if C == 'B' else 'B'
for h in range(int(H)):
    pattern = ''
    for w in range(int(W)):
        if  (w%2 == 0 and h%2 ==0) or (w%2 != 0 and h%2 !=0):
            pattern += C
        else:
            pattern += D
    print(pattern)