Given an array of n positive integers, you are asked to calculate the number of subarrays that sum up to exactly X. A subarray is a contiguous portion of an array. It is a subset of the original array, consisting of one or more adjacent elements of the original array.
Input
The first line of the input contains an integer n (1 ≤ n ≤ ).
The next line contains n space-separated integers (1 ≤ ≤ ).
The third line contains the target integer X (1 ≤ X ≤ ).
Output
The program should print the number of subarrays that sum up to X.