Let's call an undirected graph of n vertices p-interesting, if the following conditions fulfill: 

  * the graph contains exactly 2n + p edges; 
  * the graph doesn't contain self-loops and multiple edges; 
  * for any integer k (1 ≤ k ≤ n), any subgraph consisting of k vertices contains at most 2k + p edges. 



A subgraph of a graph is some set of the graph vertices and some set of the graph edges. At that, the set of edges must meet the condition: both ends of each edge from the set must belong to the chosen set of vertices. 

Your task is to find a p-interesting graph consisting of n vertices.

Input

The first line contains a single integer t (1 ≤ t ≤ 5) — the number of tests in the input. Next t lines each contains two space-separated integers: n, p (5 ≤ n ≤ 24; p ≥ 0; <image>) — the number of vertices in the graph and the interest value for the appropriate test. 

It is guaranteed that the required graph exists.

Output

For each of the t tests print 2n + p lines containing the description of the edges of a p-interesting graph: the i-th line must contain two space-separated integers ai, bi (1 ≤ ai, bi ≤ n; ai ≠ bi) — two vertices, connected by an edge in the resulting graph. Consider the graph vertices numbered with integers from 1 to n. 

Print the answers to the tests in the order the tests occur in the input. If there are multiple solutions, you can print any of them.

Examples

Input

1
6 0


Output

1 2
1 3
1 4
1 5
1 6
2 3
2 4
2 5
2 6
3 4
3 5
3 6
import java.io.*;
import java.util.*;
import java.util.List;

public class Main {
    private static StringTokenizer st;
    private static BufferedReader br;
    public static long MOD = 1000000007;

    public static void print(Object x) {
        System.out.println(x + "");
    }
    public static void printArr(long[] x) {
        StringBuilder s = new StringBuilder();
        for (int i = 0; i < x.length; i++) {
            s.append(x[i] + " ");
        }
        print(s);
    }
    public static void printArr(int[] x) {
        StringBuilder s = new StringBuilder();
        for (int i = 0; i < x.length; i++) {
            s.append(x[i] + " ");
        }
        print(s);
    }
    public static String join(Collection<?> x, String space) {
        if (x.size() == 0) return "";
        StringBuilder sb = new StringBuilder();
        boolean first = true;
        for (Object elt : x) {
            if (first) first = false;
            else sb.append(space);
            sb.append(elt);
        }
        return sb.toString();
    }

    public static String nextToken() throws IOException {
        while (st == null || !st.hasMoreTokens()) {
            String line = br.readLine();
            st = new StringTokenizer(line.trim());
        }
        return st.nextToken();
    }
    public static int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }
    public static long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }
    public static List<Integer> nextInts(int N) throws IOException {
        List<Integer> ret = new ArrayList<Integer>();
        for (int i = 0; i < N; i++) {
            ret.add(nextInt());
        }
        return ret;
    }

    public static void main(String[] args) throws IOException {
        br = new BufferedReader(new InputStreamReader(System.in));

        for (int t = nextInt(); t > 0; t--) {
            int n = nextInt();
            int p = nextInt();
            boolean[][] edge = new boolean[n][n];

            for (int u = 0; u < n; u++) {
                edge[u][(u + 1) % n] = true;
                edge[u][(u + 2) % n] = true;
                edge[(u + 1) % n][u] = true;
                edge[(u + 2) % n][u] = true;
            }
            outer : for (int u = 0; u < n; u++) {
                for (int v = u + 1; v < n; v++) {
                    if (p == 0) break outer;
                    if (edge[u][v]) continue;
                    edge[u][v] = true;
                    edge[v][u] = true;
                    p--;
                }
            }

            for (int u = 0; u < n; u++) {
                for (int v = u + 1; v < n; v++) {
                    if (edge[u][v]) print((u+1) + " " + (v+1));
                }
            }
        }
    }
}
