using System;
using System.Collections.Generic;
public class Test
{
    class Program
    {
        public static int determine_value_at_position_of_an_array(List<int> arr, int potega)
        {
            int counter = 1;
            int counter_2 = 0;
            int current_value = 0;
            
            for (; counter<= potega; counter++)
            {
                current_value = arr[counter_2];
                if (counter_2==arr.Count-1)
                {
                    counter_2 = 0;
                }
                else
                {
                    counter_2++;
                }
            }

            return current_value;
        }
        public static int get_last_number(int n)
        {
            string temp = Convert.ToString(n);
            char tempo = Convert.ToChar((temp[temp.Length - 1]));
            int result = (int)Char.GetNumericValue(tempo);
            return result;
        }
        public static List<int> Pattern_Finder(int podstawa)
        {
            List<int> sequence = new List<int>();

            int goal = (get_last_number(podstawa));
            sequence.Add(goal);

            int startowa_potega = 2;
            int temp = 0;

            while (true)
            {
                temp = pow(podstawa, startowa_potega);
                if (get_last_number(temp) == goal)
                {
                    break;
                }
                startowa_potega++;
                sequence.Add(get_last_number(temp));
            }
            
            return sequence;
        }

        public static int pow(int podstawa, int potega)
        {
            int result = 1;
            while (potega > 0)
            {
                result *= podstawa;
                potega--;
            }
            return result;
        }

        public static int Answer_Finder(int podstawa, int potega)
        {
            switch (podstawa)
            {
                case 0:
                    return 1;
                case 1:
                    return 1;
            }

            List<int> sequence = Pattern_Finder(podstawa);
            int result = determine_value_at_position_of_an_array(sequence, potega);
            return result;
        }

        public static void Main()
        {
            int n = Convert.ToInt32(Console.ReadLine());
            while (n > 0)
            {
                string[] temp_values = Console.ReadLine().Split(' ');
                int podstawa = Convert.ToInt32(temp_values[0]);
                int potega = Convert.ToInt32(temp_values[1]);
                Console.WriteLine(Answer_Finder(podstawa, potega));
            }
        }
    }
}