import java.util.*;
 
class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int testCases = sc.nextInt();
        while ((testCases--) > 0) {
            String x = sc.next();
            int lastDigit = x.charAt(x.length() - 1) - '0';
            int n = sc.nextInt();
            if (n == 0) {
                System.out.println("1");
            } else {
                n = ((n % 4) == 0) ? 4 : n % 4;
                System.out.println((int) Math.pow(lastDigit, n) % 10);
            }
        }
    }
}

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NQoxMCAxMQoxMSAyMQoxNiAzMgozNSAyMwoxMCAwCg==

5
10 11
11 21
16 32
35 23
10 0