#!/bin/python3

import sys

def printShortestPath(n, i_start, j_start, i_end, j_end):
    #  Print the distance along with the sequence of moves.
    if (i_start+i_end)%2 != 0:
        print("Impossible")
        return
    moves = []
    while i_start != i_end:
        if i_start > i_end:
            i_m = "U"
            i_start -= 2
        elif i_start < i_end:
            i_m = "L"
            i_start += 2
        if j_start > j_end:
            j_m = "L"
            j_start -= 1
        elif j_start < j_end:
            j_m = "R"
            j_start += 1
        else:
            if i_m == "U":
                j_m = "L"
                j_start -= 1
            else:
                j_m = "R"
                j_start += 1
        moves.append("{}{}".format(i_m,j_m))
         
    if j_start < j_end:
        moves.append("R")
    elif j_start > j_end:
        moves.append("L")
    print(len(moves))
    print(" ".join(moves))
    

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)