#!/bin/python3

import sys

def printShortestPath(n, i_start, j_start, i_end, j_end):
    if (i_end - i_start) % 2 != 0:
        print('Impossible')
        return
    i, j = i_start, j_start
    res = []
    while i != i_end or j != j_end:
        if i_end < i and j_end <= j:
            if j > 0:
                res.append('UL')
                i -= 2
                j -= 1
            else:
                res.append('UR')
                i -= 2
                j += 1
        elif i_end < i and j_end > j:
            res.append('UR')
            i -= 2
            j += 1
        elif i_end == i and j_end < j:
            if (j_end - j) % 2 != 0:
                print('Impossible')
                return
            res.append('L')
            j -= 2
        elif i_end == i and j_end > j:
            if (j_end - j) % 2 != 0:
                print('Impossible')
                return
            res.append('R')
            j += 2
        elif i_end > i and j_end >= j:
            if j < n-1:
                res.append('LR')
                i += 2
                j += 1
            else:
                res.append('LL')
                i += 2
                j -= 1
        elif i_end > i and j_end < j:
            res.append('LL')
            i += 2
            j -= 1
    print(len(res))
    print(' '.join(res))

if __name__ == "__main__":
    n = int(input().strip())
    i_start, j_start, i_end, j_end = input().strip().split(' ')
    i_start, j_start, i_end, j_end = [int(i_start), int(j_start), int(i_end), int(j_end)]
    printShortestPath(n, i_start, j_start, i_end, j_end)