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图灵 OJTURING / ONLINE JUDGE

#F1444. Savior

    ID: 1450 传统题 2000ms 256MiB 尝试: 0 已通过: 0 难度: 9 上传者: 标签>枚举并查集数学算法思想数据结构挑战难度共享题库Codeforces英文题面题目来源题面语言

Savior

题目描述

D. Savior
time limit per test
4 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

Misha decided to help Pasha and Akim be friends again. He had a cunning plan − to destroy all the laughy mushrooms. He knows that the laughy mushrooms can easily burst when they laugh. Mushrooms grow on the lawns. There are a[t] mushrooms on the t-th lawn.

Misha knows that the lawns where the mushrooms grow have a unique ability. A lawn (say, i) can transfer laugh to other lawn (say, j) if there exists an integer (say, b) such, that some permutation of numbers a[i],a[j] and b is a beautiful triple (ij). A beautiful triple is such three pairwise coprime numbers x,y,z, which satisfy the following condition: x2+y2=z2.

Misha wants to know on which minimal number of lawns he should laugh for all the laughy mushrooms to burst.

Input

The first line contains one integer n (1≤n≤106) which is the number of lawns. The next line contains n integers ai which are the number of mushrooms on the i-lawn (1≤ai≤107). All the numbers are different.

Output

Print a single number − the minimal number of lawns on which Misha should laugh for all the mushrooms to burst.

Examples
Input
1
2
Output
1
Input
2
1 2
Output
2
Input
2
3 5
Output
1

题目来源:fps-www.educg.net-codeforce-1-2833.xml.zip;FPS 共享题包,题包内第 952 题。保留原作者与原赛事署名。