#include<bits/stdc++.h>
using namespace std;
int T,n,a[15]={-1,-1,1,7,4,2,6,8,10,18,22,20,28,68};
int main(){
	cin>>T;
	while(T--){
		cin>>n;
		if(n<=13) cout<<a[n]<<'\n';
		else{
			cout<<a[n%7+7];
			for(int i=1;i<=n/7-1;i++) cout<<8;
			cout<<'\n';
		} 
	}
	return 0;
}
//0 1 2 3 4 5 6 7 8 9
//6,2,5,5,4,5,6,3,7,6