|시간 제한||메모리 제한||제출||정답||맞은 사람||정답 비율|
|5 초||128 MB||25||15||15||62.500%|
Two positive integers are said to be coprime if 1 is their only common divisor. Given a sequence of positive integers a1, a2, ..., an, find the number of pairs of its terms which are coprime.
The first line of input contains one integer n (1 ≤ n ≤ 1,000,000) denoting the length of the sequence. The second line contains n integers ai (1 ≤ ai ≤ 3,000,000).
Your program should output one integer representing the number of pairs (i, j) such that 1 ≤ i < j ≤ n and ai is coprime with aj.
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