B"Lunar New Year is approaching, and Bob is struggling with his homework xe2 x80 x93 a number division problem. There are n positive integers a_1, a_2, ldots, a_n on Bob's homework paper, where n is always an even number. Bob is asked to divide those numbers into groups, where each group must contain at least 2 numbers. Suppose the numbers are divided into m groups, and the sum of the numbers in the j -th group is s_j . Bob's aim is to minimize the sum of the square of s_j , that is sum_{j = 1}^{m} s_j^2. Bob is puzzled by this hard problem. Could you please help him solve it? The first line contains an even integer n ( 2 <= q n <= q 3 cdot 10^5 ), denoting that there are n integers on Bob's homework paper. The second line contains n integers a_1, a_2, ldots, a_n ( 1 <= q a_i <= q 10^4 ), describing the numbers you need to deal with. A single line containing one integer, denoting the minimum of the sum of the square of s_j , which is sum_{i = j}^{m} s_j^2, where m is the number of groups. In the first sample, one of the optimal solutions is to divide those 4 numbers into 2 groups {2, 8 }, {5, 3 } . Thus the answer is (2 + 8)^2 + (5 + 3)^2 = 164 . In the second sample, one of the optimal solutions is to divide those 6 numbers into 3 groups {1, 2 }, {1, 2 }, {1, 2 } . Thus the answer is (1 + 2)^2 + (1 + 2)^2 + (1 + 2)^2 = 27 . "...