30分求助，玄关

#include <bits/stdc++.h>
using namespace std;
int T; 
int main()
{
	cin>>T;
	while(T--)
	{
		int n;
		cin>>n;
		if(n < 2)
		{
			cout<<-1<<endl;
			continue;
		}
		if(n < 7)
		{
			if(n == 2)
				cout<<1;
			else if(n == 3)
				cout<<7;
			else if(n == 4)
				cout<<4;
			else if(n == 5)
				cout<<2;
			else
				cout<<6;
			cout<<endl;
			continue;
		}
		if(n%7 == 1)
		{
			cout<<10;
			n-=8;
		}
		else if(n%7 == 2)
		{
			cout<<1;
			n-=2;
		}
		else if(n%7 == 3)
		{
			if(n/7 >= 2)
			{
				cout<<200;
				n-=17;
			}
			else
			{
				cout<<22;
				n=0;
			}
		}
		else if(n%7 == 4)
		{
			cout<<20;
			n-=11;
		}
		else if(n%7 == 5)
		{
			cout<<2;
			n-=5;
		}
		else
		{
			cout<<6;
			n-=6;
		}
		for(int i=1; i<=n/7; i++)
			cout<<8;
		cout<<endl;
	}
	return 0;
}