#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    long long int t, a, b;
    cin >> t;

    int cycles[10][4] = {
        {0, 0, 0, 0},
        {1, 1, 1, 1},
        {2, 4, 8, 6},
        {3, 9, 7, 1},
        {4, 6, 4, 6},
        {5, 5, 5, 5},
        {6, 6, 6, 6},
        {7, 9, 3, 1},
        {8, 4, 2, 6},
        {9, 1, 9, 1}};


    while (t > 0) {
        cin >> a >> b;

        a %= 10;
        b %= 4;

        cout << cycles[a][b-1] << endl;

        t--;
    }
}