c++ language

The legend of the foundation of Vectorland talks of two integers x and y. Centuries ago, the array king placed two markers at points [x] and ly on the number line and conquered all the land in between (including the endpoints), which he declared to be Arrayland. Many years later, the vector king placed markers at points |x y, and (x + y) and conquered all the land in between (including the endpoints), which he declared to be Vectorland. He did so in such a way that the land of Arrayland was completely inside (including the endpoints) the land of Vectorland. Here |z| denotes the absolute value of z. Now, Jose is stuck on a question of his history exam: "What are the values of x and y?" Jose doesn't know the answer, but he believes he has narrowed the possible answers down to n integers a1, 2, ..., an. Now, he wants to know the number of unordered pairs formed by two different elements from these n integers such that the legend could be true if x and y were equal to these two values. Note that it is possible that Jose is wrong, and that no pairs could possibly make the legend true. Input The first line contains a single integer na 25n52.109) the number of choices. The second line contains n pairwise distinct integers aj, a2, ..., an -10