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 org.w3c.dom.ls.LSOutput;

import java.beans.IntrospectionException;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigInteger;
import java.util.*;


public class CP {
    static long startTime;
    static long endTime;
    static Boolean [] prime ;

    static class FastReader
    {
        BufferedReader br;
        StringTokenizer st;

        public FastReader()
        {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next()
        {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException  e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

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

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
    public static int lowerBound
            (Integer[] array, int length, int value) {
        int l = 0;
        int r = length;
        while (l < r) {
            int mid = (l + r) / 2;
            if (value < array[mid]) {
                r = mid;
            } else {
                l = mid + 1;
            }
        }
        return l;
    }
    public static long gcd(long a, long b){
        if (b == 0)
            return a;
        else return gcd(b, a % b);
    }
    public  static  long countDivs(long n ){
        int cn=0;
        long sqr = (long)Math.sqrt(n);
        for (long i = 1; i<=sqr ; ++i) {
            if(n%i==0){
                ++cn;
            }
        }
        cn*=2;
        if(sqr*sqr==n) cn--;
        return cn;

    }
    static void prime(int  x) {
        //sieve algorithm. nlog(log(n)).
        prime=new Boolean[ (x+1)];
        Arrays.fill(prime,true);
        prime[0] = prime[1] = false;
        for (int  i = 2; i * i <= x ; i++)
            if (prime[i])
                for (int  j = i * i; j <= x; j += i)
                    prime[j] = false;
    }
    static int[] sum;
    static void cumulitiveSum( int [] arr){
        // make the arrays one indexed.
        sum = new int[arr.length];
        sum[0]=arr[0];
        for (int i = 1; i <arr.length; i++) {
            sum[i]=arr[i]+sum[i-1];
        }
    }
    static boolean isEven(long x ){
        return x % 2 == 0;
    }
    static boolean isPrime(long x ){
        boolean flag = true;
        int sqr = (int)Math.sqrt(x);
        if(x<2) return false;
        for (int i = 2; i <=sqr; i++) {
            if(x%i==0){
                flag=false;
                break;
            }
        }
        return flag;
    }

    static long pow(long x, long n) {
        if (n == 0) {
            return 1;
        }

        long pow = pow(x, n / 2L);
        if ((n & 1) == 1) {
            return x * pow * pow%M;
        }

        return pow * pow%M;
    }
    static int T;

    public static void main(String [] args) {
        startTime = System.currentTimeMillis();
       // T = sc.nextInt();while (T--!=0)
        {
            solve();

        }
        endTime = System.currentTimeMillis();
        long duration= endTime-startTime;
        //System.out.println(duration);
    }
    static  FastReader sc = new FastReader();
    //static Scanner sc = new Scanner(System.in);
    static int M=(int )1e9+7;
    static int g (int a,int b){
        while(b!=0){
            int r = a%b;
            a=b;
            b=r;
        }
        return a;
    }
    static int factorial1( int x) {
        int total = 1;
        for (int i = 2; i <= x; i++)
            total =(total*i)%(M);
        return total;
    }
    public static void solve() {
//////////////////////////////////////////////////////////////////////
        int n=sc.nextInt(),m=sc.nextInt(),sx=sc.nextInt(),sy=sc.nextInt();
        boolean [] [] is = new boolean[n+1][m+1];
        int mm=sy;
        int nn = sx;
        while(mm>=1){
            is[nn][mm]=true;
            System.out.println(nn+ " " + mm);
            mm--;
        }
        mm=sy+1;
        while(mm<=m){//go to mostright
            is[nn][mm]=true;
            System.out.println(nn+ " " + mm);
            mm++;
        }
        nn=n;mm=m;
        while(nn>=1){
            if(nn==sx) {
                nn--;
                continue;
            }
            if(mm>=m) {
                if(mm>m) mm=m;
                while(mm>=1) {
                    if (!is[nn][mm]) {
                        System.out.println(nn + " " + mm);
                        is[nn][mm]=true;
                        mm--;
                    }


                }
            }
            else  {
                if(mm<1) mm=1;
                while(mm<=m) {
                    if (!is[nn][mm]) {
                        is[nn][mm]=true;
                        System.out.println(nn + " " + mm);
                        mm++;
                    }

                }

            }
            nn--;
        }
//////////////////////////////////////////////////////////////////////
    }

}