n=int(input())
l=map(int,raw_input().split())
ud=l[0]-l[2]
lr=l[1]-l[3]
c=0
if ud%2==0 and lr%2!=0:
	if ud>0:
		if lr>0:
			lr-=ud/2
			lr/=2
			c+=lr+ud/2
			print c
			print "UL "*(ud/2)+"L "*(lr-1)+"L"
		else:
			
			lr=abs(lr-ud/2)
			lr/=2
			c+=lr+ud/2
			print c
			print("UL "*(ud/2)+"R "*(lr-1)+"R")
	else:
		if lr>0:
			lr-=ud/2
			lr/=2
			c+=lr+ud/2
			print c
			print("UR "*(ud/2)+"L "*(lr-1)+"L")
		else:
			
			lr=abs(lr-ud/2)
			lr/=2
			c+=lr+ud/2
			print c
			print("UR "*(ud/2)+"R "*(lr-1)+"R")
else:
    if ud%4==0 and lr==0:
        if ud<0:
            print -ud/2
            print "LR LL"*(-ud/4)
        else:
            print ud/2
            print "UR UL"*(ud/4)
    elif ud%2==0 and lr==1:
            print abs(ud/2)*2
            if ud>0:
                print "UL UR "*(ud/4)+"UL"
            else:
                print "UL UR "*(ud/4)+"UR"
    else:
        print "Impossible"