#include <bits/stdc++.h>
using namespace std;
#define ll long long

int main()
{
	ll x;
	cin>>x;
	ll p,q,r,s;
	cin>>q>>p>>s>>r;
    s=x-1-s;
    q=x-1-q;
	ll k[2];
	if(s>=q){
		if(r>=p){
			if((s-q)>=2*(r-p)){
				if((s-q)%2==0){
					if(((s-q)/2+r-p)%2==0){
     					k[1]=((s-q)/2-(r-p))/2;
     					k[0]=((s-q)/2+(r-p))/2;
						if(k[1]>p){
    						cout<<k[0]+k[1]<<endl;
							for(ll i=0;i<p;i++){
 								cout<<"UL"<<" ";
							}
							for(ll i=p;i<k[1];i++){
 								cout<<"UR"<<" "<<"UL"<<" ";
							}
							for(ll i=k[1]-p;i<k[0];i++){
 								cout<<"UR"<<" ";
							}
							cout<<endl;
						}
						else{
							cout<<k[0]+k[1]<<endl;
							for(ll i=0;i<k[1];i++){
	 							cout<<"UL"<<" ";
							}
							for(ll i=0;i<k[0];i++){
	 							cout<<"UR"<<" ";
							}
							cout<<endl;
						}
					}
					else
					{
						cout<<"Impossible"<<endl;
					}
				}
				else{
					cout<<"Impossible"<<endl;
				}
			}
			else{
				if((s-q)%2==0){
					k[0]=(s-q)/2;
					if((r-p-k[0])%2==0){
						k[1]=(r-p-(k[0]))/2;
						cout<<k[0]+k[1]<<endl;
						for(ll i=0;i<k[0];i++){
							cout<<"UR"<<" ";
						}
						for(ll i=0;i<k[1];i++){
							cout<<"R"<<" ";
						}
						cout<<endl;
					}
					else{
						cout<<"Impossible"<<endl;
					}
				}
				else{
					cout<<"Impossible"<<endl;
				}
			}
		}
		else{
			if((s-q)>=2*(p-r)){
		    	if((s-q)%2==0){
					if(((s-q)/2+p-r)%2==0){
		     			k[1]=((s-q)/2-(p-r))/2;
		     			k[0]=((s-q)/2+(p-r))/2;
						if(k[1]>p){
							cout<<k[0]+k[1]<<endl;
							for(ll i=0;i<p;i++){
		 						cout<<"UL"<<" ";
							}
							for(ll i=p;i<k[0];i++){
		 						cout<<"UR"<<" "<<"UL"<<" ";
							}
							for(ll i=k[0]-p;i<k[1];i++){
		 						cout<<"UR"<<" ";
							}
							cout<<endl;
						}
						else{
							cout<<k[0]+k[1]<<endl;
							for(ll i=0;i<k[0];i++){
		 						cout<<"UL"<<" ";
							}
							for(ll i=0;i<k[1];i++){
		 						cout<<"UR"<<" ";
							}
							cout<<endl;
						}
					}
					else{
						cout<<"Impossible"<<endl;
					}
				}
				else{
					cout<<"Impossible"<<endl;
				}
			}
			else{
				if((s-q)%2==0){
					k[0]=(s-q)/2;
					if((p-r-k[0])%2==0){
						k[1]=(p-r-(k[0]))/2;
						cout<<k[0]+k[1]<<endl;
						for(ll i=0;i<k[0];i++){
							cout<<"UL"<<" ";
						}
						for(ll i=0;i<k[1];i++){
							cout<<"L"<<" ";
						}
						cout<<endl;
					}
					else{
						cout<<"Impossible"<<endl;
					}
				}
				else{
					cout<<"Impossible"<<endl;
				}
			}
		}
	}
	else{	
		if(r>=p){
			if((q-s)>=2*(r-p)){
				if((q-s)%2==0){
					if(((q-s)/2+r-p)%2==0){
				    	k[1]=((q-s)/2-(r-p))/2;
				    	k[0]=((q-s)/2+(r-p))/2;
						if(k[0]+p>x-1){
				    		cout<<k[0]+k[1]<<endl;
							for(ll i=0;i<x-1-p;i++){
						 		cout<<"LR"<<" ";
							}
							for(ll i=x-1-p;i<k[0];i++){
						 		cout<<"LL"<<" "<<"LR"<<" ";
							}
							for(ll i=k[0]+p+1-x;i<k[1];i++){
						 		cout<<"LL"<<" ";
							}
							cout<<endl;
						}
						else{
							cout<<k[0]+k[1]<<endl;
							for(ll i=0;i<k[0];i++){
						 		cout<<"LR"<<" ";
							}
							for(ll i=0;i<k[1];i++){
						 		cout<<"LL"<<" ";
							}
							cout<<endl;
						}
					}
					else{
						cout<<"Impossible"<<endl;
					}
				}
				else{
					cout<<"Impossible"<<endl;
				}
			}
			else{
				if((q-s)%2==0){
					k[0]=(q-s)/2;
					if((r-p-k[0])%2==0){
						k[1]=(r-p-(k[0]))/2;
						cout<<k[0]+k[1]<<endl;
						for(ll i=0;i<k[1];i++){
							cout<<"R"<<" ";
						}
						for(ll i=0;i<k[0];i++){
							cout<<"LR"<<" ";
						}
						cout<<endl;
					}
					else{
						cout<<"Impossible"<<endl;
					}
				}
				else{
					cout<<"Impossible"<<endl;
				}
			}
		}
		else{
			if((q-s)>=2*(p-r)){
			    if((q-s)%2==0){
					if(((q-s)/2+p-r)%2==0){
					    k[1]=((q-s)/2-(p-r))/2;
					    k[0]=((q-s)/2+(p-r))/2;
						if(k[1]+p>x-1){
							cout<<k[0]+k[1]<<endl;
							for(ll i=0;i<x-1-p;i++){
						 		cout<<"LR"<<" ";
							}
							for(ll i=x-1-p;i<k[1];i++){
						 		cout<<"LL"<<" "<<"LR"<<" ";
							}
							for(ll i=k[1]+p+1-x;i<k[0];i++){
						 		cout<<"LL"<<" ";
							}
							cout<<endl;
						}
						else{
							cout<<k[0]+k[1]<<endl;
							for(ll i=0;i<k[1];i++){
						 		cout<<"LR"<<" ";
							}
							for(ll i=0;i<k[0];i++){
						 		cout<<"LL"<<" ";
							}
							cout<<endl;
						}
					}
					else{
						cout<<"Impossible"<<endl;
					}
				}
				else{
					cout<<"Impossible"<<endl;
				}
			}
			else{
				if((q-s)%2==0){
					k[0]=(q-s)/2;
					if((p-r-k[0])%2==0){
						k[1]=(p-r-(k[0]))/2;
						cout<<k[0]+k[1]<<endl;
						for(ll i=0;i<k[0];i++){
							cout<<"LL"<<" ";
						}
						for(ll i=0;i<k[1];i++){
							cout<<"L"<<" ";
						}
						cout<<endl;
					}
					else{
						cout<<"Impossible"<<endl;
					}
				}
				else{
					cout<<"Impossible"<<endl;
				}
			}
		}
	}
}