The king is left alone on the chessboard. In spite of this loneliness, he doesn't lose heart, because he has business of national importance. For example, he has to pay an official visit to square *t*. As the king is not in habit of wasting his time, he wants to get from his current position *s* to square *t* in the least number of moves. Help him to do this.

In one move the king can get to the square that has a common side or a common vertex with the square the king is currently in (generally there are 8 different squares he can move to).
The first line contains the chessboard coordinates of square *s*, the second line — of square *t*.

Chessboard coordinates consist of two characters, the first one is a lowercase Latin letter (from a to h), the second one is a digit from 1 to 8.
# function to get the position of a square on the board
def get_pos(square):
    col = ord(square[0]) - ord('a')
    row = int(square[1]) - 1
    return (row, col)

# function to get the square for a given position on the board
def get_square(pos):
    col = chr(pos[1] + ord('a'))
    row = str(pos[0] + 1)
    return col + row

# read input
start = input().strip()
end = input().strip()

# get starting and ending positions
start_pos = get_pos(start)
end_pos = get_pos(end)

# calculate distance in rows and columns
dr = abs(start_pos[0] - end_pos[0])
dc = abs(start_pos[1] - end_pos[1])

# calculate diagonal moves and remaining non-diagonal moves
diag_moves = min(dr, dc)
non_diag_moves = abs(dr - dc)

# output number of moves
total_moves = diag_moves + non_diag_moves
print(total_moves)

# output the moves
while diag_moves > 0:
    # move diagonally
    if start_pos[0] > end_pos[0]:
        if start_pos[1] > end_pos[1]:
            print("LD")
            start_pos = (start_pos[0] - 1, start_pos[1] - 1)
        else:
            print("RD")
            start_pos = (start_pos[0] - 1, start_pos[1] + 1)
    else:
        if start_pos[1] > end_pos[1]:
            print("LU")
            start_pos = (start_pos[0] + 1, start_pos[1] - 1)
        else:
            print("RU")
            start_pos = (start_pos[0] + 1, start_pos[1] + 1)
    diag_moves -= 1

while non_diag_moves > 0:
    # move horizontally or vertically
    if start_pos[0] > end_pos[0]:
        print("U")
        start_pos = (start_pos[0] - 1, start_pos[1])
    else:
        print("D")
        start_pos = (start_pos[0] + 1, start_pos[1])
    non_diag_moves -= 1

    if non_diag_moves == 0:
        break

    if start_pos[1] > end_pos[1]:
        print("L")
        start_pos = (start_pos[0], start_pos[1] - 1)
    else:
        print("R")
        start_pos = (start_pos[0], start_pos[1] + 1)
    non_diag_moves -= 1
