n = int(input())
i1,i2,j1,j2 = map(int,input().split(" "))
if (i1-j1)%2 != 0 or ((i1-j1)/2)%2 -(i2-j2)%2 != 0:
    print("Impossible")
else:
    r = 0
    comp = []
    if i1 >= j1 and i2 >= j2:
        x = i1-j1
        y = i2 - j2
        t = int(x/2)
        if t <= y:
            r += t
            comp += ["UL"] * t
            r += int((y-t)/2)
            comp += ["L"] * int((y-t)/2)
    elif i1 >= j1 and i2 < j2:
        x = i1-j1
        y = j2-i2
        t = int(x/2)
        if t <= y:
            r += t
            comp += ["UR"] * t
            r += int((y-t)/2)
            comp += ["R"] * int((y-t)/2)
    elif i1 < j1 and i2 < j2:
        x = j1-i1
        y = j2-i2
        t = int(x/2)
        if t <= y:
            r += t
            comp += ["LR"] * t
            r += int((y-t)/2)
            comp += ["R"] * int((y-t)/2)
        else:
            u = t-y
            
            
    print(r)
    print(" ".join(map(str,comp)))