import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) {
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        try {
            int T = Integer.parseInt(br.readLine().trim());
            for (int i = 0; i < T; ++i) {
                long start = System.currentTimeMillis();
                Runner runner = new Runner(br, bw);
                runner.run();
                runner.flush();
                long end = System.currentTimeMillis();
            }
            br.close();
            bw.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

class Solution {
    int solution(int A, int B) {
        int res = 1;
        for (int i = 0; i < B; ++i) {
            res *= A;
            res %= 10;
        }
        return res == 0 ? 10 : res;
    }
}

class Runner {
    final Reader reader;
    final BufferedWriter bw;

    final int A,B;

    Runner(BufferedReader br, BufferedWriter bw) {
        this.reader = new Reader(br);
        this.bw = bw;
        try {
            var ab = reader.readInts();
            A = ab[0];
            B = ab[1];

        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public void flush() {
        try {
            bw.write('\n');
            bw.flush();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public void run() throws IOException {
        var sol = new Solution();
        var res = sol.solution(A,B);
        bw.write(String.valueOf(res));
    }
}

class Reader {
    private BufferedReader br;

    public Reader(BufferedReader br) {
        this.br = br;
    }

    public int[] readInts() throws IOException {
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");
        int cnt = st.countTokens();
        int[] ints = new int[cnt];
        for (int i = 0; i < cnt; ++i) {
            ints[i] = Integer.parseInt(st.nextToken());
        }
        return ints;
    }

    public long[] readLongs() throws IOException {
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");
        int cnt = st.countTokens();
        long[] longs = new long[cnt];
        for (int i = 0; i < cnt; ++i) {
            longs[i] = Long.parseLong(st.nextToken());
        }
        return longs;
    }

    public int[][] readIntArrays() throws IOException {
        return br.lines().map(s -> Arrays.stream(s.split(" "))
                .mapToInt(Integer::parseInt)
                .toArray())
                .toArray(int[][]::new);
    }
}