Sum Pairs to Target

You are given a list of integers nums and an integer target. In one operation we can remove any two numbers in nums if the pair sums to target. Return the maximum number of operations we can perform.

Constraints

• n ≤ 100,000 where n is the length of nums

https://binarysearch.com/problems/Sum-Pairs-to-Target

Examples

Example 1

Input

• nums = [1, 3, 5, 3, 7]
• target = 6

Output

• answer = 2

Explanation

We can pair [1, 5] and [3, 3].

Example 2

Input

• nums = [6]
• target = 6

Output

• answer = 0

Explanation

There’s no two numbers that sum to 6

Solution