代码全RE:

#include<bits/stdc++.h>
using namespace std;
int n,num[9]={-1,-1,1,7,4,2,6,8};
int s(){
	cin>>n;
	if(n==1) cout<<-1<<'\n';
	else if(n<=7) cout<<num[n]<<'\n';
	else{
		int cnt=n/7,r=n%7;
		if(r==1) cout<<"10",cnt--;
		else if(r==3){
			if(cnt>=2) cout<<"200",cnt-=2;
			else cout<<"22",cnt--;
		}
		else if(r==4) cout<<"20",cnt--;
		else if(r>0) cout<<num[r];
		while(cnt--) cout<<8;
		cout<<'\n';
	}
}
int main(){
	int t;
	cin>>t;
	while(t--) s();
	return 0;
}