Given an array of $n$ integers, your task is to count the number of subarrays having sum $x$ .
The first input line has two integers $n$ and $x$ : the size of the array and the target sum $x$ .
The next line has $n$ integers $a_1,a_2,\dots,a_n$ : the contents of the array.
Print one integer: the required number of subarrays.