def possible(si, sj, ei, ej):
    return (si & 1 == ei & 1) and ((si >> 1) & 1 == (ei >> 1) & 1) == (sj & 1 == ej & 1)


n = int(input())
starti, startj, endi, endj = [int(x) for x in input().strip().split()]
UL, UR, R, LR, LL, L = [0] * 6

if not possible(starti, startj, endi, endj):
    print('Impossible')
    exit()

# check out of bounds
while starti != endi or startj != endj:
    if starti < endi:
        if startj <= endj and startj+1 < n:
            LR += 1
            starti += 2
            startj += 1
        else:
            LL += 1
            starti += 2
            startj -= 1
    elif starti > endi:
        if startj <= endj and startj+1 < n:
            UR += 1
            starti -= 2
            startj += 1
        else:
            UL += 1
            starti -= 2
            startj -= 1
    elif startj < endj:
        R += (endj - startj) >> 1
        startj = endj
    else:
        L += (startj - endj) >> 1
        startj = endj

ans = []
ans += ['UL'] * UL
ans += ['UR'] * UR
ans += ['R'] * R
ans += ['LR'] * LR
ans += ['LL'] * LL
ans += ['L'] * L

print(len(ans))
print(*ans)