#include <bits/stdc++.h>
using namespace std;

int main()
{
	int n, a[10005];
	int sum, sq, ans; 
	cin >> n;
	for(int i = 1; i <= n; i++)
	{
		cin >> a[i];
	}
	for (int i = 1; i <= n - 1; i++) 
	{
	    for (int j = i + 1; j <= n; j++) 
		{
	        int sum = a[i] + a[j];
	        int sq = sqrt(sum);
	        if (sq * sq == sum)
	        {
	            ans++;
			} 
		}
	}	
	cout << sq; 
	return 0;
}