LKP '18 Contest 2 P2 - Secret Signal

View as PDF

Submit solution


Points: 5
Time limit: 3.0s
Memory limit: 64M

Author:
Problem type

The Alliance, which was at war with Collea, uses a highly convoluted method to encrypt their messages which involves signaling a long series of positive integers. Despite their best attempts, Collea was unable to effectively decrypt their messages. However, they have found out that a sequence of these signals might be an encrypted message if and only if the sum of the integers signalled is a multiple of K. The Alliance had just signalled N integers. Help the Collean Armed Forces find how many continuous intervals of these signals might contain an encrypted message.

Constraints

1 \le N \le 200\,000
1 \le K \le 50\,000
1 \le a_i \le 1\,000\,000

Input Specification

The first line contains two positive integers, N and K.
The next line contains N positive integers, the numbers a_1, a_2, \dots, a_N.

Output Specification

Print one integer, the number of intervals of the signals whose elements sum to a multiple of K.

Sample Input

5 4
60 2 7 1 2

Sample Output

4

Comments

There are no comments at the moment.