#!/bin/python3

import sys

def p(n, i1, j1, i2, j2,c,a):
    if abs(i2-i1)%2!=0:
        print("Impossible")
        return
    if abs(i2-i1)%4==0:
        if (j2-j1)%2!=0: 
            print("Impossible")
            return
    else:
        if (j2-j1)%2!=1:
            print("Impossible")
            return
    if i1-i2==0 and j1-j2==0:
        print(c)
        for i in range(len(a)):
            print(a[i],end=' ')
        return
    
    if (j2-j1)<=0 and (i2-i1)<0:
        a.append("UL")
        p(n,i1-2,j1-1,i2,j2,c+1,a)
    elif (j2-j1)>0 and (i2-i1)<0:
        a.append("UR")
        p(n,i1-2,j1+1,i2,j2,c+1,a)
    elif (j2-j1)>0 and (i2-i1)>=0:
        a.append("R")
        p(n,i1,j1+2,i2,j2,c+1,a)
    elif (j2-j1)>=0 and (i2-i1)>0:
        a.append("LR")
        p(n,i1+2,j1+1,i2,j2,c+1,a)
    elif (j2-j1)<0 and (i2-i1)>0:
        a.append("LL")
        p(n,i1+2,j1-1,i2,j2,c+1,a)
    else:
        a.append("L")
        p(n,i1,j1-2,i2,j2,c+1,a)

if __name__ == "__main__":
    c=0
    a=[]
    n = int(input().strip())
    i_start, j_start, i_end, j_end = input().strip().split(' ')
    i_start, j_start, i_end, j_end = [int(i_start), int(j_start), int(i_end), int(j_end)]
    p(n, i_start, j_start, i_end, j_end,c,a)