import java.io.InputStreamReader;
import java.io.IOException;
import java.util.Arrays;
import java.io.PrintStream;
import java.io.BufferedReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Rubanenko
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		CandidateWalk solver = new CandidateWalk();
		solver.solve(1, in, out);
		out.close();
	}
}

class CandidateWalk {

    void getState(int[] coordinates, int state, int n, int d) {
        for (int i = 0; i < n; i++) {
            coordinates[i] = state % d;
            state /= d;
        }
    }

    long countAnswer(int n, int d) {
        if (d == 1) {
            return 0;
        }
        int[] deg = new int[n];
        deg[0] = 1;
        for (int i = 1; i < n; i++) {
            deg[i] = deg[i - 1] * d;
        }
        int numberOfStates = 1;
        for (int i = 1; i <= n; i++) {
            numberOfStates *= d;
        }
        CheckerTools.ensureLimits(numberOfStates, 1, 1 << 16);
        long[] f = new long[numberOfStates];
        Arrays.fill(f, Long.MAX_VALUE);
        f[0] = 0;
        int[] coordinates = new int[n];
        for (int state = 0; state < numberOfStates; state++) {
            getState(coordinates, state, n, d);
            long curSum = 0;
            long curXor = 0;
            for (int i = 0; i < n; i++) {
                curSum += coordinates[i];
                curXor ^= coordinates[i];
            }
            for (int i = 0; i < n; i++) {
                if (coordinates[i] < d - 1) {
                    f[state + deg[i]] = Math.min(f[state + deg[i]], f[state] + (curSum + 1) * (curXor ^ coordinates[i] ^ (coordinates[i] + 1)));
                }
            }
        }
        return f[f.length - 1];
    }

    public void solve(int testNumber, InputReader in, PrintWriter out) {
        int testCases = in.nextInt();
        CheckerTools.ensureLimits(testCases, 1, 20);
        for (int test = 1; test <= testCases; test++) {
            int n = in.nextInt();
            int d = in.nextInt();
            CheckerTools.ensureLimits(n, 1, 10);
            out.println(countAnswer(n, d));
        }
    }
}

class CheckerTools {

    public static void exit(String message) {
        System.err.println(message);
        System.exit(1);
    }

    public static void ensureCondition(boolean condition, String message) {
        if (!condition) {
            exit(message);
        }
    }

    public static void ensureLimits(long n, long l, long r) {
        if (n < l ||n > r) {
            ensureCondition(l <= n && n <= r, "Number " + Long.toString(n) + " is out of range [" + Long.toString(l) + ", " + Long.toString(r) + "]");
        }
    }

}

class InputReader {
    private BufferedReader reader;
    private StringTokenizer tokenizer;

    public InputReader(InputStream inputStream) {
        reader = new BufferedReader(new InputStreamReader(inputStream));
    }

    public String nextLine() {
        String line = null;
        try {
            line = reader.readLine();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return line;
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens())
            tokenizer = new StringTokenizer(nextLine());
        return tokenizer.nextToken();
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }
}