side of the suitcase will be smallest if they arranged in 2 x 2 way so find all possible sides of that arrangement
side1 = a [ 0 ] + a [ 3 ] NEW_LINE side2 = a [ 1 ] + a [ 2 ] NEW_LINE side3 = a [ 0 ] + a [ 1 ] NEW_LINE side4 = a [ 2 ] + a [ 3 ] NEW_LINE