n = input()
i1, j1, i2, j2 = map(int,raw_input().split())

def fun():
    if abs(i2 - i1)%2 == 1:
        print "Impossible"
    elif abs(i2 - i1)%4 == 0 and abs(j2 - j1)%2 == 1:
        print "Impossible"
    elif abs(i2 - i1)%4 == 2 and abs(j2 - j1)%2 == 0:
        print "Impossible"
    else:
        ans = 0
        ar = []
        while(i1!=i2 or j1!=j2):
            ans += 1
            ar.append(dir())
        print ans
        print " ".join(str(t) for t in ar)
            

def dir():
    global i1, i2, j1, j2
    if i2<i1 and j2<=j1:
        i1 -= 2
        j1 -= 1
        return "UL"
    if i2<i1 and j2>j1:
        i1 -= 2
        j1 += 1
        return "UR"
    if i1==i2 and j2>j1:
        j1 += 2
        return "R"
    if i2>i1 and j2>=j1:
        i1 += 2
        j1 += 1
        return "LR"
    if i2>i1 and j2<j1:
        i1 += 2
        j1 -= 1
        return "LL"
    if i1==i2 and j2<j1:
        j1 -= 2
        return "L"


fun()