ws, hs, c = input().split()
w = int(ws)
h = int(hs)
sub = 'WB'
if c == 'B':
  sub = 'BW'
src = sub * ((w + 1) // 2 + 1)
src0 = src[:w]
src1 = src[1:w+1]
for i in range(h):
  if i % 2 == 0:
    print(src0)
  else:
    print(src1)