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.
s = input()
t = input()

delta_col = ord(t[0]) - ord(s[0])
delta_row = int(t[1]) - int(s[1])

num_moves = min(abs(delta_col), abs(delta_row))

if delta_col > 0:
    delta_col -= num_moves
    if delta_row > 0:
        moves_list = ['RU' for __ in range(num_moves)]
        delta_row -= num_moves
    else:
        moves_list = ['RD' for __ in range(num_moves)]
        delta_row += num_moves

else:
    delta_col += num_moves
    if delta_row > 0:
        moves_list = ['LU' for __ in range(num_moves)]
        delta_row -= num_moves

    else:
        moves_list = ['LD' for __ in range(num_moves)]
        delta_row += num_moves

num_rem_moves = max(abs(delta_col), abs(delta_row))
num_moves += num_rem_moves

if delta_col > 0:
    moves_list += ['R' for __ in range(num_rem_moves)]
elif delta_col < 0:
    moves_list += ['L' for __ in range(num_rem_moves)]
elif delta_row > 0:
    moves_list += ['D' for __ in range(num_rem_moves)]
elif delta_row < 0:
    moves_list += ['U' for __ in range(num_rem_moves)]

print(num_moves)
print(*moves_list, sep='\n')
