import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    static void printShortestPath(int n, int i_start, int j_start, int i_end, int j_end) {
        //  Print the distance along with the sequence of moves.
        int a=0;
        int p =0;
        if(i_start>i_end){
            a = i_start - i_end;
        }
        if(i_end > i_start){
            a = i_end - i_start;
        }
        if (a%2==1){
           System.out.print("Impossible");
        }
        if (a%2==0){
           System.out.println((a/2)+1);
        }
        if(a%2==0){
            for(int i=0;i<a-2;){
               System.out.print("UL "); 
                i = i+2;
            }
             System.out.print("UL L"); 
        }
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int i_start = in.nextInt();
        int j_start = in.nextInt();
        int i_end = in.nextInt();
        int j_end = in.nextInt();
        printShortestPath(n, i_start, j_start, i_end, j_end);
        in.close();
    }
}