You are given an array integer $A$ of length $n$. Find the number of pairs $(i, j)$ that $A_i = A_j$ and $i \neq j$.

Input

• The first line contains an integer $n$.
• The second line contains $n$ integers $A_i$.

Output

• One integer is the number of pairs you found.

Constraints

• $1 \le n \le 10^5$.
• $1 \le A_i \le 10^5$.

Example

Input:

5
1 2 2 1 1

Output:

4