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()


def Char2Num(ch):
    return ord(ch) - ord('A') + 1   #Using offset to make 'A' to 1

def Num2Char(num):
    return chr(ord('A')+num-1)   #  chr and ord are opposites.


s_x = Char2Num(s[0])
s_y = int(s[1])

t_x = Char2Numb(t[0])
t_y = int(t[1])

steps = []    #initialize the steps as empty list

x = s_x
y = s_y

while x < t_x and y < t_y:  #if t is right upper (RU)
    steps.append("RU")
    x += 1
    y += 1
while x < t_x and y < t_y:  #if t is left down (LD)
    steps.append("LD")
    x -= 1
    y -= 1
while x > t_x and y > t_y  #if t is right down (RD)
    steps.append("RD")
    x -= 1
    y += 1
while x > t_x and y < t_y
    steps.append("LU")
    x -= 1
    y += 1
while x < t_x:  #because we execute diagonal first, means either x is at the target or y is at the target
    steps.append("R")
    x += 1
while x > t_x: #Means we go left
    steps.append("L")
    x -= 1
while y < t_y
    steps.append("U")
    y += 1
while y > t_y
    steps.append("D")
    y -= 1
    
    
print(len(steps))
for step in steps:
    print(step)