give integer array num 2n integer group integer n pair a1 b1 a2 b2 bn sum minai bi maximize Return maximized sum Example 1input num 1432output 4explanation all possible pairing ignore order element are1 1 4 2 3 min1 4 min2 3 1 2 32 1 3 2 4 min1 3 min2 4 1 2 33 1 2 3 4 min1 2 min3 4 1 3 4so maximum possible sum 4example 2input num 626512output 9explanation the optimal pair 2 1 2 5 6 6 min2 1 min2 5 min6 6 1 2 6 9 Constraints1 n 104numslength 2 n104 numsi 104