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:
    import java.io.*;
import java.util.Arrays;
import java.util.InputMismatchException;


/*
By : SSD
*/


public class B {
    long mod = (long) (1e9 + 7);

    static class InputReader1 {

        private final InputStream st;
        private final byte[] buf = new byte[8192];
        private int cc, sc;
        private SpaceCharFilter f;

        public InputReader1(InputStream st) {
            this.st = st;
        }

        public int t() {
            if (sc == -1)
                throw new InputMismatchException();
            if (cc >= sc) {
                cc = 0;
                try {
                    sc = st.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (sc <= 0)
                    return -1;
            }
            return buf[cc++];
        }

        public int nextInt() {
            int c = t();
            while (isSpaceChar(c)) {
                c = t();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = t();
            }
            int res = 0;
            do {
                res *= 10;
                res += c - '0';
                c = t();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public long nextLong() {
            int c = t();
            while (isSpaceChar(c)) {
                c = t();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = t();
            }
            long res = 0;
            do {
                res *= 10;
                res += c - '0';
                c = t();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public int[] nextIntArray(int n) {
            int a[] = new int[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextInt();
            }
            return a;
        }

        public String readString() {
            int c = t();
            while (isSpaceChar(c)) {
                c = t();
            }
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = t();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public String nextLine() {
            int c = t();
            while (isSpaceChar(c))
                c = t();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = t();
            } while (!isEndOfLine(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (f != null)
                return f.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        private boolean isEndOfLine(int c) {
            return c == '\n' || c == '\r' || c == -1;
        }

        public interface SpaceCharFilter {
            boolean isSpaceChar(int ch);
        }
    }

    class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0) {
                    writer.print(' ');
                }
                writer.print(objects[i]);
            }
        }

        public void println(Object... objects) {
            print(objects);
            writer.println();
        }

        public void close() {
            writer.close();
        }
    }

    InputReader1 sc;
    OutputWriter out;

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

    void run() throws Exception {


        sc = new InputReader1(System.in);
        out = new OutputWriter(System.out);

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

    }


    private void solve() {
       int  n=sc.nextInt(),m=sc.nextInt(),xx=sc.nextInt(),yy=sc.nextInt();
       int x=xx,y=yy;
        for (int i = 0; i <n ; i++) {
            for (int j = 0; j <m ; j++) {
                out.println(x+" "+y);
                y++;
                if (y>m)
                    y=1;


            }
            x++;
            y--;
            if(y==0)
                y=m;
            if (x>n)
                x=1;

        }


    }

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

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