Mr. Hikiko will react with a “Not Bad”, if you can solve this problem.
An array is a Not Bad array if the sum of all of its element is equal to its length. For example, this array $[1, -1, 3]$ is a Not Bad array since the sum of all its element is $3$ (which is equal to its length).
Given an array. Find the number of non-empty Not Bad sub-arrays of this array.
A sub-array is a contiguous part of an array. For example, consider the array $[1, 2, 3]$. There are 6 non-empty sub-arrays. The sub-arrays are $[1]$, $[2]$, $[3]$, $[1, 2]$, $[2, 3]$, $[1, 2, 3]$.
Input
The first line will contain $N$ ($1 \le N \le 10^6$), the length of the array.
The next line will contain the elements of the array ($-10^9 \le \texttt{each element} \le 10^9$).
Output
Print the number of non-empty Not Bad sub-arrays of given array.
Sample
| Input | Output |
|---|---|
5 1 -1 3 -1 2 | 4 |
