- Time limit: 1.00 s
- Memory limit: 512 MB
Given an array of positive integers, your task is to count the number of subarrays having sum .
Input
The first input line has two integers and : the size of the array and the target sum .
The next line has integers : the contents of the array.
Output
Print one integer: the required number of subarrays.
Constraints
Example
Input:
5 7 2 4 1 2 7
Output:
3