W, H, C = input().split()
W = int(W)
H = int(H)
memo = ['B', 'W']
memo.remove(C)
other = memo.pop()

ans = [['A'] * (W) for _ in range(H)]

for i in range(H):
    for j in range(W):
        if (i + j)%2 == 0:
            ans[i][j] = C
        else:
            ans[i][j] = other
for a in ans:
    print(''.join(a))