#include<fstream.h>
#include<string.h>
using namespace std;
int main()
{
	ifstream f("cifra.in");
	ofstream g("cifra.out");
	unsigned t,i,aux,v1[10]={7,1,5,2,8,3,9,2,8,7},v2[10]={7,1,7,0,6,1,7,4,8,7},rez;
	char s[101];
	f>>t;
	for(i=1;i<=t;i++)
	{
		f>>s;
		if(strlen(s)==1)
		{
			aux=s[0]-'0';
			rez=v1[aux];
		}
		else
		{
			aux=(s[strlen(s)-2]-'0')*10+s[strlen(s)-1]-'0';
			if(aux/10%2==0) rez=((aux/10-1)*7%10+v2[aux%10])%10;
			else rez=((aux/10-1)*7%10+v1[aux%10])%10;
		}
		g<<rez<<"\n";
	}
	return 0;
}