Write a function numpairs that accepts two arguments, a target number and a list of numbers.

The function then returns the count of pairs of numbers from the list that sum to the target

number. In the first example the answer is $2$ because the pairs $(0,3)$ and $(1,2)$ both sum to $3.$ The

pair can be two of the same number, e$.$g$.(2,2)$ but only if the two $2\text{'}$s are separate twos in the list.

In the last example below, there are three $2\text{'}$s$,$ so there are three different pairs $(2,2)$ so there are

$5$ pairs total that sum to $4.$ Sample usage: