package com.company;
import java.util.Scanner;
public class Main {
 
    public static void main(String[] args) {
        int n, temp = 1;
        Scanner scanner = new Scanner(System.in);
        n = scanner.nextInt();
        int [] numbers = new int[n];
        for (int i = 0; i < n; i++) {
            Scanner scanner1 = new Scanner(System.in);
            int a = scanner1.nextInt();
            Scanner scanner2 = new Scanner(System.in);
            int b = scanner2.nextInt();
            for (int j = 1; j <= b; j++) {
                temp *= a;
            }
            numbers[i] = temp;
            temp = 1;
        }
        for (int i = 0; i < n; i++) {
            System.out.println(numbers[i] % 10);
        }
    }
}

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