Given an array A of n integers. Count the number of contiguous subsequences such that all values in the subsequence appear an odd number of times.
### Input
- The first line contains two integers n.
- The second line contains n integers Ai.
### Output
- Print an integer, the number of subsequences that satisfy the condition.
### Constraints
- 1≤n,Ai≤105.
### Example
Input:
3122
Output:
4
