#include <fstream>
#include <string>
#include <math.h>
using namespace std;

int main () {

ifstream in ("cifra.in");
ofstream out ("cifra.out");

int t, i, j;
string numero;
in >> t;
int values[10][10];
values[0][0] = 0;
int k = 0, last = 0, temp, l;
for (i = 0; i < 10;i++)
{
	for (j = 0; j < 10; j++)
	{	
		if (i != 0 || j != 0)
		{	
			temp = k % 10;
			l = 1;
			while (l != k)
			{
				temp = temp * (k % 10);
				temp %= 10;
				l++;
			}
			values[i][j] = (last + temp) % 10;
			last = values[i][j];
		}
		k++;
	}
}

for (i = 0; i < t; i++)
{
	in >> numero;
	if (numero.size() < 2)
		out << values[0][numero[0] - '0'];
	else
		out << values[*(numero.begin()) - '0'][*(numero.begin() + 1) - '0'];
	out << endl;
}
return 0;
}