#include <bits/stdc++.h>
using namespace std;
#define ll long long int

void mainSolve()
{
	ll n;
	cin>>n;
	if(n == 1ll)
	{
		cout<<0<<endl;
		return;
	}
	ll temp = n;
	ll count = 0;
	while(temp%2==0)
	{
		temp/=2;
		++count;
	}
	if(count == 0)
	{
		cout<<1<<endl;
		return;
	}
	else if(count % 2 == 1)
	{
		cout<<-1<<endl;
		return;
	}
	ll sq = sqrt(n);
	if(sq*sq == n)
		cout<<1<<endl;
	else
		cout<<2<<endl;
}

int main()
{
  int t;
  cin>>t;
  while (t--)
  {
    mainSolve();
  }
  return 0;
}