Given an integer array `nums` of `2n` integers, group these integers into `n` pairs `(a1, b1), (a2, b2), ..., (an, bn)` such that the sum of `min(ai, bi)` for all `i` is maximized. Return the maximized sum.

Example 1:

    Input: nums = [1,4,3,2]
    Output: 4
    Explanation: All possible pairings (ignoring the ordering of elements) are:
    1. (1, 4), (2, 3) -> min(1, 4) + min(2, 3) = 1 + 2 = 3
    2. (1, 3), (2, 4) -> min(1, 3) + min(2, 4) = 1 + 2 = 3
    3. (1, 2), (3, 4) -> min(1, 2) + min(3, 4) = 1 + 3 = 4
    So the maximum possible sum is 4.

Example 2:

    Input: nums = [6,2,6,5,1,2]
    Output: 9
    Explanation: The optimal pairing is (2, 1), (2, 5), (6, 6). min(2, 1) + min(2, 5) + min(6, 6) = 1 + 2 + 6 = 9.

Constraints:

- `1 <= n <= 104`
- `nums.length == 2 * n`
- `-104 <= nums[i] <= 104`