#include<bits/stdc++.h>
using namespace std;
int b[14]={-1,-1,1,7,4,2,0,8,10,18,22,20,28,68};
//0-6 1-2 2-5 4-4 6-6 7-3 8-7
int main()
{
	int t;
	cin>>t;
	while(t--)
	{
		int n;
		cin>>n;
		if(n<=13)
			cout<<b[n]<<endl;
		else if(n%7==0)
		{
			for(int i=1;i<=n/7;i++)
				cout<<8;
			cout<<endl;
		}
		else
		{
			int p=n/7;
			int m=n%7+7;
			cout<<b[m];
			for(int i=1;i<p;i++)
				cout<<8;
			cout<<endl;
		}
	}
}