# Enter your code here. Read input from STDIN. Print output to STDOUT
def get_path(si,sj,di,dj,path):
    #print si,sj,di,dj,path
    if si==di and sj==dj:
        return path
    if si>di and sj>=dj:
        path.append("UL")
        si-=2
        sj-=1
        if si<0 or sj>n:
            return("Impossible")
        path=get_path(si,sj,di,dj,path)
    elif si>di and sj<=dj:
        path.append("UR")
        si-=2
        sj+=1
        if si<0 or sj>n:
            return("Impossible")
        path=get_path(si,sj,di,dj,path)
    elif si==di and sj<dj:
        path.append("R")
        sj+=2
        if si<0 or sj>n:
            return("Impossible")
        path=get_path(si,sj,di,dj,path)
    elif si<di and sj<=dj:
        path.append("LR")
        si+=2
        sj+=1
        if si<0 or sj>n:
            return("Impossible")
        path=get_path(si,sj,di,dj,path)
    elif si<di and sj>=dj:
        path.append("LL")
        si+=2
        sj-=1
        if si<0 or sj>n:
            return("Impossible")
        path=get_path(si,sj,di,dj,path)
    elif si==di and sj>dj:
        path.append("L")
        sj-=2
        if si<0 or sj>n:
            return("Impossible")
        path=get_path(si,sj,di,dj,path)
    if si==di and sj==dj:
        return(path)
    if dj==sj and (si==di+1 or si+1==di):
        return("Impossible")
    if di==si and (sj==dj+1 or sj+1==dj):
        return("Impossible")
    return path

n=input()
si,sj,di,dj=map(int,raw_input().split(" "))
#UL, UR, R, LR, LL, L
path=[]
try:    
    k=get_path(si,sj,di,dj,path)
except:
    k="Impossible"
if k=="Impossible":
    print k
else:
    print len(k)
    for item in k:
        print item,