w, h, c = map(str, input().split(' '))

w = int(w)
h = int(h)

tile = [
    [ '' for i in range(w) ]
    for j in range(h)
]

if c == 'B':
    c_other = 'W'
else:
    c_other = 'B'

tile_after = []
for i, tile_row in enumerate(tile):
    char_now = ''
    for j, tile_col in enumerate(tile_row):
        if (i + j)%2 == 0:
            char_now += c
        else:
            char_now += c_other
        
        if j == w -1:
            tile_after.append(char_now)

for row in tile_after:
    print(row)