Given an array with length of positive integers, find the amount of unordered pairs of indices there are such that is an irreducible root.
A root is reducible if it has a power other than 1 as a factor.
Input Specification
The first line will contain two integers, , and .
The next line will contain integers, the array .
Output Specification
You are to output one line, the number of unordered pairs.
Subtasks
Subtask 1 [30%]
Subtask 2 [70%]
No further constraints.
Sample Input
4 3
2 3 4 9
Sample Output
4
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