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:

<image>

Solution (in JAVA):

Solution:
/*
 * Author Ayub Subhaniya
 */

import java.io.*;
import java.util.*;

public class Solution {

    private InputStream in;
    private PrintWriter out;


    private long mod = (long) 1e9 + 7;
    int MAX = (int) 1e6 + 7;
    private boolean visited[][];
    private int moves = 0;

    private String INPUT = "";

    private void solve() {
//        int testcases = ni();
        int testcases = 1;
        for (int test = 1; test <= testcases; test++) {
            int n = ni();
            int m = ni();
            int x = ni();
            int y = ni();

            visited = new boolean[n + 1][m + 1];
            visit(x, y);

            // jump to 1st row
            visit(x, 1);

            Pair point = new Pair(1, 1);
            for (int i=1; i<=m; i++){
                point = next(point, n, m, (i % 2 == 0 ? -1 : +1), 0);
                point = new Pair(point.x, point.y + 1);
            }

        }
    }

    private Pair next(Pair point, int n, int m, int dx, int dy) {
        int a = point.x;
        int b = point.y;

        Pair last_point = null;

        while (isValid(a, b, n, m)) {

            if (!visited[a][b]) {
                last_point = new Pair(a, b);
                visit(a, b);
            }
            a += dx;
            b += dy;
        }

        return last_point;
    }

    private void visit(int a, int b){
        visited[a][b] = true;
        out.println(a + " " + b);
    }

    private boolean isValid(int x, int y, int n, int m) {
        return x >= 1 && y >= 1 && x <= n && y <= m;
    }

    class Pair {
        int x;
        int y;

        Pair(int a, int b) {
            x = a;
            y = b;
        }

        @Override
        public boolean equals(Object o) {
            Pair other = (Pair) o;
            return x == other.x && y == other.y;
        }

        public String toString() {
            return x + " " + y;
        }

        @Override
        public int hashCode() {
            return Objects.hash(x, y);
        }
    }


    private void run() throws Exception {
        oj = INPUT.length() == 0;
        in = oj ? System.in : new FileInputStream(INPUT);
        out = new PrintWriter(System.out);

        long s = System.currentTimeMillis();
        solve();
        out.flush();
        tr(System.currentTimeMillis() - s + "ms");

    }

    public static void main(String[] args) throws Exception {
        new Solution().run();
    }

    private byte[] inbuf = new byte[1024];
    public int lenbuf = 0, ptrbuf = 0;

    private int readByte() {
        if (lenbuf == -1)
            throw new InputMismatchException();
        if (ptrbuf >= lenbuf) {
            ptrbuf = 0;
            try {
                lenbuf = in.read(inbuf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (lenbuf <= 0)
                return -1;
        }
        return inbuf[ptrbuf++];
    }

    private boolean inSpaceChar(int c) {
        return !(c >= 33 && c <= 126);
    }

    private int skip() {
        int b;
        while ((b = readByte()) != -1 && inSpaceChar(b))
            ;
        return b;
    }

    private double nd() {
        return Double.parseDouble(ns());
    }

    private char nc() {
        return (char) skip();
    }

    private String ns() {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while (!(inSpaceChar(b))) { // when nextLine, (inSpaceChar(b) && b != ' ')
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private char[] ns(int n) {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while (p < n && !(inSpaceChar(b))) {
            buf[p++] = (char) b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }

    private char[][] nm(int n, int m) {
        char[][] map = new char[n][];
        for (int i = 0; i < n; i++)
            map[i] = ns(m);
        return map;
    }

    private int[] na(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = ni();
        return a;
    }

    private int ni() {
        int num = 0, b;
        boolean minus = false;
        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
            ;
        if (b == '-') {
            minus = true;
            b = readByte();
        }

        while (true) {
            if (b >= '0' && b <= '9') {
                num = num * 10 + (b - '0');
            } else {
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private long nl() {
        long num = 0;
        int b;
        boolean minus = false;
        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
            ;
        if (b == '-') {
            minus = true;
            b = readByte();
        }

        while (true) {
            if (b >= '0' && b <= '9') {
                num = num * 10 + (b - '0');
            } else {
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private boolean oj = System.getProperty("ONLINE_JUDGE") != null;

    private void tr(Object... o) {
        if (!oj)
            System.out.println(Arrays.deepToString(o));
    }

}