#!/bin/python3

import sys


def printShortestPath(n, i_start, j_start, i_end, j_end):
    # order to print: UL, UR, R, LR, LL, L
    if i_start & 1 != i_end & 1 or (abs(i_start - i_end)&3 != 0 and j_start == j_end):
        print("Impossible")
        return
    # try to find shortest path. First try to get up
    res = []
    pos_i = i_start
    pos_j = j_start

    # special case for speed up:
    if j_start == j_end:
        if i_start > i_end:
            # we need to go up
            # can we go left first?
            if j_start > 0:
                order = ["UL", "UR"]
            else:
                order = ["LR", "LL"]
        else:
            if j_start < n:
                order =  ["LR", "LL"]
            else:
                order = ["UL", "UR"]
        res = order * (abs(i_start - i_end) // 4)
    else:
        # calculat max numbers of possible UL/UR operations:
        if pos_i > i_end:
            if pos_j > j_end:
                max_num = (pos_i - i_end) // 2
                res.extend(["UL"]*max_num)
                pos_i -= 2 * max_num
                pos_j -= max_num
            else:
                max_num = (pos_i - i_end) // 2
                res.extend(["UR"]*max_num)
                pos_i -= 2 * max_num
                pos_j += max_num
        # next we go for R and LR operations. For this we need to make sure that we can still go up as much as needed
        if pos_j < j_end:
            max_lr = min((i_end - pos_i) // 2, j_end - pos_j)
            max_r = (j_end - pos_j - max_lr) // 2
            res.extend(["R"] * max_r)
            res.extend(["LR"] * max_lr)
            pos_i += 2 * max_lr
            pos_j += max_lr + 2 * max_r
        # at this point we only need to go left, so first we move up as much as possible
        if pos_i < i_end:
            max_num = (i_end - pos_i) // 2
            res.extend(["LL"]*max_num)
            pos_i += 2 * max_num
            pos_j += max_num
        # now all thats left:
        max_num = (pos_j - j_end) // 2
        res.extend(["L"] * max_num)

    print(len(res))
    print(*res)

if __name__ == "__main__":
    n = int(input().strip())
    i_start, j_start, i_end, j_end = 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)