import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Back_1009 {
    public static void main(String[] args) throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        StringTokenizer st;
        int T = Integer.parseInt(br.readLine());

        for (int i = 0; i < T; i++) {
            st = new StringTokenizer(br.readLine());
            int a = Integer.parseInt(st.nextToken());
            int b = Integer.parseInt(st.nextToken());
            int result = 1;

            for (int j = 1; j <= b; j++) {
                result = result * a % 10;
            }
            result = result == 0 ? 10 : result;
            sb.append(result).append("\n");
        }
        System.out.println(sb);
        br.close();
    }
}