given an integer k and a list of integers, count tha number of distinct valid pairs of integers(a, b ) in the list for which a + k = b. Two pairs of integers (a, b) and (c, d) are considered distinct if at least one element of (a, b) does not also belong to (c, d). Note that the elements in a pair might be the same element in the array. An instance of this is below where k=0

[4, 1, 2, 2, 5, 2]