#!/bin/python3

import sys

s = ""  
i = 0
def printShortestPath(n, i_start, j_start, i_end, j_end,first=True):
    global i
    global s
    print(s,file=sys.stderr)
    if(i_start == i_end and j_start == j_end):
        print(i)
        print(s)
        return
    i+= 1
    if(first):
        s+=" "
    if((i_start - i_end) % 2 == 1):
        s+="Impossible"
        print(s)
        return
    elif(((i_start - i_end)/2 % 2) != ((j_start - j_end) % 2)):
        s+="Impossible"
        print(s)
        return
    elif(i_start > i_end):
        if(j_start > 0 and (j_end - j_start + 1 <= (i_start - i_end)/2)):
            s+="UL"
            printShortestPath(n,i_start - 2, j_start - 1, i_end, j_end)
        elif(j_start < n and (j_start - j_end + 1 <= (i_start - i_end)/2)):
            s+="UR"
            printShortestPath(n,i_start - 2, j_start + 1, i_end, j_end)
    elif(j_end - j_start > (i_end - i_start)/2):
        s+="R"
        printShortestPath(n, i_start, j_start + 2, i_end, j_end)
    elif(i_start < i_end):
        if(j_start < n and (j_start - j_end + 1 <= (i_end - i_start)/2)):
            s+="LR"
            printShortestPath(n,i_start + 2, j_start + 1, i_end, j_end)
        elif(j_start > 0 and (j_end - j_start + 1 <= (i_end - i_start)/2)):
            s+="LL"
            printShortestPath(n,i_start + 2, j_start - 1, i_end, j_end)
    else:
        s+="L"
        printShortestPath(n,i_start,j_start - 2, i_end, j_end)
        
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,False)