#include <fstream>
#include <cstring>

using namespace std;

int main()
{
	ifstream in("cifra.in");
	ofstream out("cifra.out");

	int T, v[10], val, s;
	char nr[100];

	in >> T;
	in.get();

	v[0] = 0;
	for(int i = 1; i < 10; i++)
	{
		v[i] = 1;
		for(int j = 0; j < i; j++)
			v[i] *= i;
		v[i] = v[i]%10;
		v[i] = (v[i]+v[i-1])%10;
	}
	v[0] = v[9];

	for(int i = 0; i < T; i++)
	{
		in.getline(nr, 101);
		s = strlen(nr);
		val = v[(nr[s-1]-'0')];
		if(s > 1)
			val += v[0]*(nr[s-2]-'0');
		val = val % 10;
		out << val << endl;
	}

}