def convert(s): return [ord(s[0]) - 65, int(s[1]) - 1] visited = [[0] * 6 for _ in range(6)] cor = convert(input()) start = cor[:] visited[cor[0]][cor[1]] = 2 for _ in range(35): cur = convert(input()) x_diff, y_diff = abs(cor[0] - cur[0]), abs(cor[1] - cur[1]) if visited[cur[0]][cur[1]] or x_diff in [0, 3] or x_diff + y_diff != 3: print('Invalid') exit() visited[cur[0]][cur[1]] = 1 cor = cur x_..