# Enter your code here. Read input from STDIN. Print output to STDOUT
n=input()
x,y,x1,y1=[int(x) for x in raw_input().split()]
x1-=x
y1-=y
ans=[]
def go(x1,y1):
    if x1==0 and y1==0:
        return
    elif x1==0:
        if y1>=0:
            ans.append("R")
            go(x1,y1-2)
        elif y1<=0:
            ans.append("L")
            go(x1,y1+2)
    elif x1>=0 and y1>=0:
        ans.append("LR")
        go(x1-2,y1-1)
    elif x1>=0 and y1<=0:
        ans.append("LL")
        go(x1-2,y1+1)
    elif x1<=0 and y1>=0:
        ans.append("UR")
        go(x1+2,y1-1)
    else:
        ans.append("UL")
        go(x1+2,y1+1)
        
        
if x1%2==1:
    print "Impossible"
elif (y1%2)!=((x1/2)%2):
    print "Impossible"
else:
    
    go(x1,y1)
    print len(ans)
    print " ".join(ans)