#!/bin/python

import sys

def printShortestPath(n, i_start, j_start, i_end, j_end):
    #  Print the distance along with the sequence of moves.
    vertical_diff = i_end - i_start
    if abs(vertical_diff) % 2 != 0:
        print "Impossible"
        return
    horizontal_diff = j_end - j_start
    if horizontal_diff % 2 != (vertical_diff / 2) % 2:
        print "Impossible"
        return
    free_move = abs(vertical_diff) / 2
    target_move = abs(horizontal_diff)
    if horizontal_diff > 0:
        direction = "R"
    else:
        direction = "L"
    if vertical_diff < 0:
        prefix = "U"
    else:
        prefix = "L"
    move = min(free_move, target_move)
    if i_start == 0:
        rep = [prefix + "R", prefix + "L"]
    else:
        rep = [prefix + "L", prefix + "R"]
    command = (rep * ((free_move - move) / 2) 
            + [(prefix + direction)] * move 
            + [direction] * (max(target_move - free_move, 0) / 2))
    print len(command)
    print " ".join(command)
    

if __name__ == "__main__":
    n = int(raw_input().strip())
    i_start, j_start, i_end, j_end = raw_input().strip().split(' ')
    i_start, j_start, i_end, j_end = [int(i_start), int(j_start), int(i_end), int(j_end)]
    printShortestPath(n, i_start, j_start, i_end, j_end)