#!/bin/python3

import sys

def printShortestPath(n, i_start, j_start, i_end, j_end):
    #  Print the distance along with the sequence of moves.
    # UL (1 left, 2 up), UR (1 right, 2 up), R (2 right), LR (1 right, 2 down), LL (1 left, 2 down), L (2 left)
    if abs(i_end - i_start) < 2 and abs(j_end - j_start) < 2:
        print('Impossible')
        return
    if (abs(j_end - j_start)%2 == 0 and j_end != j_start) or abs(i_end - i_start)%2 != 0:
        print('Impossible')
        return
    
    num_moves = 0
    span = ''
    # i - rows
    # j - cols
    #  j j j
    #i| . . .
    #i| . . .
    # i_start 0
    # j_start 3 4
    # i_end 4
    # j_end 3
    while i_end != i_start or j_end != j_start:
        if i_end - i_start == 0:  # side only:
            if j_end - j_start > 0:  # right
                span = ' '.join([span, 'R'])
                j_start += 2
            else:  # left
                span = ' '.join([span, 'L'])
                j_start -= 2
        elif i_end - i_start < 0:  # up
            if j_end - j_start == 0:  # double move case
                if j_start != 0:
                    span = ' '.join([span, 'UL'])
                    j_start -= 1
                else:
                    span = ' '.join([span, 'UR'])
                    j_start += 1
            elif j_end - j_start < 0:  # up-left
                span = ' '.join([span, 'UL'])
                j_start -= 1
            else:  # up-right
                span = ' '.join([span, 'UR'])
                j_start += 1
            i_start -= 2   
        else:  # down
            if j_end - j_start == 0:  # double move case
                if j_start != n - 1:
                    span = ' '.join([span, 'LR'])
                    j_start += 1
                else:
                    span = ' '.join([span, 'LL'])
                    j_start -= 1
            elif j_end - j_start < 0:  # down-left
                span = ' '.join([span, 'LL'])
                j_start -= 1
            else:  # down-right
                span = ' '.join([span, 'LR'])
                j_start += 1
            i_start += 2   
        num_moves += 1
        
    print(num_moves)
    print(span.strip())
    

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)