Imagine, you have an array of integers of size N. At each index of this array is a unique integer from 1 to N. You have to calculate how many pairs of indexes (i, j) exists in the array such that:
The first line contains a positive integer N (1 ≤ N ≤ 105), the size of the array.
The next N lines have one number each, the content of the index i in the array.
Output a single number, the result of this problem.
2 1 2