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

void printShortestPath(vector<string>& sequence, int i_start, int j_start, int i_end, int j_end) {
    if((abs(i_end - i_start) == 1 && j_start == j_end) || (abs(j_end - j_start) == 1 && i_start == i_end)) {
        cout << "Impossible";
        return;
    }
    
    if(i_start == i_end && j_start == j_end) {
        cout << sequence.size() << endl;
        for(int i = 0; i < sequence.size(); i++)
            cout << sequence[i] << " ";
        return;
    }
    
    if(i_start > i_end && j_start >= j_end) {
        sequence.push_back("UL");
        printShortestPath(sequence, i_start-2, j_start-1, i_end, j_end);
    }
    else if(i_start > i_end && j_start < j_end) {
        sequence.push_back("UR");
        printShortestPath(sequence, i_start-2, j_start+1, i_end, j_end);
    }
    else if(i_start == i_end && j_start < j_end) {
        sequence.push_back("R");
        printShortestPath(sequence, i_start, j_start+2, i_end, j_end);
    }
    else if(i_start < i_end && j_start <= j_end) {
        sequence.push_back("LR");
        printShortestPath(sequence, i_start+2, j_start+1, i_end, j_end);
    }
    else if(i_start < i_end && j_start > j_end) {
        sequence.push_back("LL");
        printShortestPath(sequence, i_start+2, j_start-1, i_end, j_end);
    }
    else if(i_start == i_end && j_start > j_end) {
        sequence.push_back("L");
        printShortestPath(sequence, i_start, j_start-2, i_end, j_end);
    }
        
}

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n;
    cin >> n;
    
    int i_start, i_end, j_start, j_end;
    cin >> i_start >> j_start >> i_end >> j_end;
    
    vector<string> sequence;
    printShortestPath(sequence, i_start, j_start, i_end, j_end);
    
    return 0;
}