//
// Author: Harsh_Vasoya, DA-IICT
//

#include <bits/stdc++.h>

#define sync_off std::ios_base::sync_with_stdio(false); cin.tie(NULL);
#define lli long long int
#define hashmap unordered_map
#define hashset unordered_set

#define all(v) v.begin(),v.end()
#define pb push_back

#define pii pair<int,int>
#define mp make_pair
#define F first
#define S second

#define si(n)	 scanf("%d",&n)
#define sii(n,m) scanf("%d%d",&n,&m)
#define slli(n)  scanf("%lld",&n)
#define forn(i,a,b) for(int i=a;i<b;i++)

const int mod = 10000009;
const lli MOD = 1000000007;
const int INF = INT_MAX;
int DEBUG = 0;

using namespace std;

int main()
{
	int n;
	si(n);

	pair<int,int> start,end;
	sii(start.F,start.S);
	sii(end.F,end.S);

	if(abs(end.F-start.F)%2!=0){
		printf("Impossible\n");
		return 0;
	}

	pair<int,int> curr = start;
	vector<int> path;

	while(curr != end){
		if(curr.F > end.F){
			if(curr.S >= end.S){	// UL
				curr.F -= 2;
				curr.S -= 1;
				path.pb(1);
			}
			else{
				curr.F -= 2;		// UR
				curr.S += 1;
				path.pb(2);
			}
		}
		else if(curr.F == end.F){
			if(abs(curr.S-end.S)%2!=0){
				printf("Impossible\n");
				return 0;
			}

			if(curr.S > end.S){		// L
				curr.S -= 2;
				path.pb(6);
			}
			else{					// R
				curr.S += 2;
				path.pb(3);
			}
		}
		else{
			if(curr.S <= end.S){	// LR
				curr.F += 2;
				curr.S += 1;
				path.pb(4);
			}
			else{
				curr.F += 2;		// LL
				curr.S -= 1;
				path.pb(5);
			}
		}
	}

	sort(all(path));

	printf("%d\n", path.size());
	forn(i,0,path.size()){
		switch(path[i]){
			case 1: printf("UL "); break;
			case 2: printf("UR "); break;
			case 3: printf("R "); break;
			case 4: printf("LR "); break;
			case 5: printf("LL "); break;
			case 6: printf("L "); break;
		}
	}

    return 0;
}