#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include<stdbool.h>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n,a,i,h,b,m,k;
    cin>>n;
    int x1,y1,x2,y2;
    cin>>y1>>x1;
    cin>>y2>>x2;
/*    int s[8][2];
    
    bool A[n][n];
    for(i=0;i<n;i++){
        for(j=0;j<n;j++){
            A[i][j]=false;
        }
    }
/*    pair <int,int> cord; */
/*    vector<pair<int,int>> v1;
    v1.push_back(make_pair(x1,y1));*/
    b=y2-y1;
    if(b%2!=0){
        cout<<"Impossible";
        return 0;
    }
    b=b/2;
    a=x2-x1;
    h=abs(a)-abs(b);
    m=abs(b)+abs(h/2);
    if(h%2!=0){
        cout<<"Impossible";
        return 0;
    }
    cout<<m<<"\n";
    k=abs(b);
    for(i=0;i<k;i++){
        if(b>=0){
            cout<<"L";
        }
        else{
            cout<<"U";
        }
        if(a>=0){
            cout<<"R";
            a--;
        }
        else{
            cout<<"L";
            a++;
        }
        cout<<" ";
    }
    if(a>0){
        for(i=0;i<abs(h/2);i++){
            cout<<"R ";
        }
    }
    else if(a<0){
        for(i=0;i<abs(h/2);i++){
            cout<<"L ";
        }
    }
    return 0;
}