Based on the Unified State Examination 2017
Problem
Given a set of N natural numbers. It is necessary to determine the number of pairs of elements (ai, aj) of this set, in which \(1 <= i < j <= N\) and the product of the elements is a multiple of 14.
Write a time and memory efficient program to solve this problem.
Input data
The first line of the input specifies the number of numbers N (\(1 < N <= 10000\)). Each of the following N lines contains one natural number not exceeding 1000.
Imprint data
Print the answer to the problem.
Examples
| # |
Input |
Output |
| 1 |
5
14
7
7
2
19 |
6 |