#include<fstream>
#include<string.h>
using namespace std;
ifstream fi("cifra.in");
ofstream fo("cifra.out");
int A[]={1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0};
int V[]={0,4,8,2,6};
char S[101];
char *p;
int n,i,rez,x;
int main()
{
	fi>>n;
	for(i=1; i<=n; i++)
	{
		rez=0;
		fi>>S;
		if(strlen(S)<=2)
			p=S;
		else
			p=S+strlen(S)-2;
		x=atoi(p);
		for(i=0; i<x%20; i++)
			rez=rez+A[i];
		fo<<(V[x/20]+rez)%10<<"\n";
	}
	fi.close();
	fo.close();
	return 0;
}