Problem: Boboniu likes playing chess with his employees. As we know, no employee can beat the boss in the chess game, so Boboniu has never lost in any round.

You are a new applicant for his company. Boboniu will test you with the following chess question:

Consider a n× m grid (rows are numbered from 1 to n, and columns are numbered from 1 to m). You have a chess piece, and it stands at some cell (S_x,S_y) which is not on the border (i.e. 2 ≤ S_x ≤ n-1 and 2 ≤ S_y ≤ m-1).

From the cell (x,y), you can move your chess piece to (x,y') (1≤ y'≤ m, y' ≠ y) or (x',y) (1≤ x'≤ n, x'≠ x). In other words, the chess piece moves as a rook. From the cell, you can move to any cell on the same row or column.

Your goal is to visit each cell exactly once. Can you find a solution?

Note that cells on the path between two adjacent cells in your route are not counted as visited, and it is not required to return to the starting point.

Input

The only line of the input contains four integers n, m, S_x and S_y (3≤ n,m≤ 100, 2 ≤ S_x ≤ n-1, 2 ≤ S_y ≤ m-1) — the number of rows, the number of columns, and the initial position of your chess piece, respectively.

Output

You should print n⋅ m lines.

The i-th line should contain two integers x_i and y_i (1 ≤ x_i ≤ n, 1 ≤ y_i ≤ m), denoting the i-th cell that you visited. You should print exactly nm pairs (x_i, y_i), they should cover all possible pairs (x_i, y_i), such that 1 ≤ x_i ≤ n, 1 ≤ y_i ≤ m.

We can show that under these constraints there always exists a solution. If there are multiple answers, print any.

Examples

Input


3 3 2 2


Output


2 2
1 2
1 3
2 3
3 3
3 2
3 1
2 1
1 1


Input


3 4 2 2


Output


2 2
2 1
2 3
2 4
1 4
3 4
3 3
3 2
3 1
1 1
1 2
1 3

Note

Possible routes for two examples:

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Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;

public class B {

    static class Pair<U extends Comparable<U>, V extends Comparable<V>>
            implements Comparable<Pair<U,V>>{

        public final U a;
        public final V b;

        private Pair(U a, V b) {
            this.a = a;
            this.b = b;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o)
                return true;
            if (o == null || getClass() != o.getClass())
                return false;

            Pair<?, ?> pair = (Pair<?, ?>) o;
            if (!a.equals(pair.a))
                return false;
            return b.equals(pair.b);
        }

        @Override
        public int hashCode() {
            return 31 * a.hashCode() + b.hashCode();
        }

        @Override
        public String toString() {
            return "(" + a + ", " + b + ")";
        }

        @Override
        public int compareTo(Pair<U, V> o) {
            if(this.a.equals(o.a)){
                return getV().compareTo(o.getV());
            }
            return getU().compareTo(o.getU());
        }
        private U getU() {
            return a;
        }
        private V getV() {
            return b;
        }
        static void print(Pair[] pairs){
            for(int i=0;i<pairs.length;i++){
                System.out.print(pairs[i]+" ");
            }
            System.out.println();
        }
        static void print(Pair[][] pairs){

            for(int i=0;i<pairs.length;i++){
                for(int j=0;j<pairs[0].length;j++) {
                    System.out.print(pairs[i] + " ");
                }
                System.out.println();
            }
        }
    }

    static BufferedReader inp = new BufferedReader(new InputStreamReader(System.in));
    static BufferedWriter out = new BufferedWriter(new OutputStreamWriter(System.out));

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


        String[] s1 = inp.readLine().split(" ");
        int row = Integer.parseInt(s1[0]);
        int col = Integer.parseInt(s1[1]);
        int a = Integer.parseInt(s1[2]);
        int b = Integer.parseInt(s1[3]);


        int visited = a;
        int init = b;

        out.write(a+" "+b+"\n");

        for(int j=1;j<=col;j++) {
            if(j!=init) {
                out.write(visited + " " + j+"\n");
                b = j;
            }
        }


        for(int i=1;i<=row;i++){
            if(i!=visited){
                int g = b;
                out.write(i+" "+g+"\n");
                for(int j=1;j<=col;j++) {
                    if(j!=b) {
                        out.write(i + " " + j+"\n");
                        g = j;
                    }
                }
                b = g;
            }
        }

        out.flush();
    }


    static void merge(int arr[], int l, int m, int r)
    {
        // Find sizes of two subarrays to be merged
        int n1 = m - l + 1;
        int n2 = r - m;

        /* Create temp arrays */
        int L[] = new int [n1];
        int R[] = new int [n2];

        /*Copy data to temp arrays*/
        for (int i=0; i<n1; ++i)
            L[i] = arr[l + i];
        for (int j=0; j<n2; ++j)
            R[j] = arr[m + 1+ j];


        /* Merge the temp arrays */

        // Initial indexes of first and second subarrays
        int i = 0, j = 0;

        // Initial index of merged subarry array
        int k = l;
        while (i < n1 && j < n2)
        {
            if (L[i] <= R[j])
            {
                arr[k] = L[i];
                i++;
            }
            else
            {
                arr[k] = R[j];
                j++;
            }
            k++;
        }

        /* Copy remaining elements of L[] if any */
        while (i < n1)
        {
            arr[k] = L[i];
            i++;
            k++;
        }

        /* Copy remaining elements of R[] if any */
        while (j < n2)
        {
            arr[k] = R[j];
            j++;
            k++;
        }
    }

    // Main function that sorts arr[l..r] using
    // merge()
    static void sort(int arr[], int l, int r)
    {
        if (l < r)
        {
            // Find the middle point
            int m = (l+r)/2;

            // Sort first and second halves
            sort(arr, l, m);
            sort(arr , m+1, r);

            // Merge the sorted halves
            merge(arr, l, m, r);
        }
    }



    static void print(int[] array) {
        for (int j = 0; j < array.length; j++) {
            System.out.print(array[j] + " ");
        }
        System.out.println();
    }

    static void print(int[][] array) {
        for (int i = 0; i < array.length; i++) {
            for (int j = 0; j < array[0].length; j++) {
                System.out.print(array[i][j] + " ");
            }
            System.out.println();
        }
    }

    static void print(boolean[] array) {
        for (int j = 0; j < array.length; j++) {
            System.out.print(array[j] + " ");
        }
        System.out.println();
    }

    static void print(boolean[][] array) {
        for (int i = 0; i < array.length; i++) {
            for (int j = 0; j < array[0].length; j++) {
                System.out.print(array[i][j] + " ");
            }
            System.out.println();
        }
    }

    static void print(long[] array) {
        for (int j = 0; j < array.length; j++) {
            System.out.print(array[j] + " ");
        }
        System.out.println();
    }

    static void print(long[][] array) {
        for (int i = 0; i < array.length; i++) {
            for (int j = 0; j < array[0].length; j++) {
                System.out.print(array[i][j] + " ");
            }
            System.out.println();
        }
    }

    static void print(String[] array) {
        for (int j = 0; j < array.length; j++) {
            System.out.print(array[j] + " ");
        }
        System.out.println();
    }

    static void print(String[][] array) {
        for (int i = 0; i < array.length; i++) {
            for (int j = 0; j < array[0].length; j++) {
                System.out.print(array[i][j] + " ");
            }
            System.out.println();
        }
    }

}