def main():
    W, H, flag = input().split()
    W, H = int(W), int(H)
    for x in range(H):
        l = []
        for y in range(W):
            if flag == 'B':
                l += flag
                flag = 'W'
            else:
                l += flag
                flag = 'B'
        print(''.join(l))
        if W % 2 == 0:
            if flag == 'B':
                flag = 'W'
            else:
                flag = 'B'

if __name__ == '__main__':
    main()