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.*;
    import java.math.*;
     
    public class Solution {
     
        InputStream is;
        PrintWriter o;
        /////////////////// CODED++ BY++ ++ ++ ++ BHAVYA++ ARORA++ ++ ++ ++ FROM++ JAYPEE++ INSTITUTE++ OF++ INFORMATION++ TECHNOLOGY++ ////////////////
     
    ///////////////////////// Make it work, make it right, make it fast. Make it work, make it right, make it fast. Make it work, make it right, make it fast. Make it work, make it right, make it fast. /////////////////
     
    	class pair
    	{
    		int a;
    		int b;
    		pair(int x,int y)
    		{
    			a=x;
    			b=y;
    		}
    	}
        
        void solve() {
        	int n=ni();
        	int m=ni();
        	int x=ni()-1;
        	int y=ni()-1;


        	ArrayList<pair>al=new ArrayList<pair>();
        	boolean mat[][]=new boolean[n][m];
        	boolean vis[]=new boolean[m];
        	int i=x;
        	int j=y;

        	for(j=y;j<m;j++)
        	{


        		if(j%2==0)
        		{
        			
        			while(i<n&&mat[i][j]==false)
        			{
        				mat[i][j]=true;
        				al.add(new pair(i+1,j+1));
        				i++;


        			}
        			i=n-1;

        		}
        		else
        		{
        			while(i>0&&mat[i][j]==false)
        			{
        				mat[i][j]=true;
        				al.add(new pair(i+1,j+1));
        				i--;
        			}
        			i=1;
        		}
        	}
        	//al.add(new pair(1,m));
        	i=0;
        	j=m-1;
        	for(j=m-1;j>=1;j--)
        	{
        		mat[i][j]=true;
        		al.add(new pair(i+1,j+1));
        	}
        	i=0;
        	for(j=0;j<n;j++)
        	{
        		if(mat[i][j]==true)
        		{
        			break;
        		}

        		if(j%2==0)
        		{
        			
        			while(i<n&&mat[i][j]==false)
        			{
        				mat[i][j]=true;
        				al.add(new pair(i+1,j+1));
        				i++;


        			}
        			i=n-1;

        		}
        		else
        		{
        			while(i>0&&mat[i][j]==false)
        			{
        				mat[i][j]=true;
        				al.add(new pair(i+1,j+1));
        				i--;
        			}
        			i=1;
        		}

        	}
        	for(pair p:al)
        	{
        		o.println(p.a+" "+p.b);
        	}

           
     
        
     
            
            
     
            
     
     
        }
     
     
     
     
     
     
       
     
     
        
     
     
     
     
     
     
     
     
     
     
     
     
        
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
        //---------- I/O Template ----------
        
        public static void main(String[] args) { new Solution().run(); }
        void run() { 
            is = System.in; 
            o = new PrintWriter(System.out);
            solve();
            o.flush();
        }
        
        byte input[] = new byte[1024];
        int len = 0, ptr = 0;
        
        int readByte() { 
            if(ptr >= len) { ptr = 0; 
                try { len = is.read(input); } 
                catch(IOException e) { throw new InputMismatchException(); } 
                if(len <= 0) { return -1; } 
            } return input[ptr++];
        }
        boolean isSpaceChar(int c) { return !( c >= 33 && c <= 126 ); }
        int skip() { 
            int b = readByte(); 
            while(b != -1 && isSpaceChar(b)) { b = readByte(); } 
            return b;
        }
        
        char nc() { return (char)skip(); }
        String ns() { 
            int b = skip(); 
            StringBuilder sb = new StringBuilder(); 
            while(!isSpaceChar(b)) { sb.appendCodePoint(b); b = readByte(); } 
            return sb.toString();
        }
        String nLine() { 
            int b = skip(); 
            StringBuilder sb = new StringBuilder(); 
            while( !(isSpaceChar(b) && b != ' ') ) { sb.appendCodePoint(b); b = readByte(); } 
            return sb.toString();
        }
        int ni() { 
            int n = 0, b = readByte(); 
            boolean minus = false; 
            while(b != -1 && !( (b >= '0' && b <= '9') || b == '-')) { b = readByte(); } 
            if(b == '-') { minus = true; b = readByte(); } 
            if(b == -1) { return -1; }  //no input 
            while(b >= '0' && b <= '9') { n = n * 10 + (b - '0'); b = readByte(); } 
            return minus ? -n : n;
        }
        long nl() { 
            long n = 0L;    int b = readByte(); 
            boolean minus = false; 
            while(b != -1 && !( (b >= '0' && b <= '9') || b == '-')) { b = readByte(); } 
            if(b == '-') { minus = true; b = readByte(); } 
            while(b >= '0' && b <= '9') { n = n * 10 + (b - '0'); b = readByte(); } 
            return minus ? -n : n;
        }
     
        double nd() { return Double.parseDouble(ns()); }
        float nf() { return Float.parseFloat(ns()); }
        int[] nia(int n) { 
            int a[] = new int[n]; 
            for(int i = 0; i < n; i++) { a[i] = ni(); } 
            return a;
        }
        long[] nla(int n) { 
            long a[] = new long[n]; 
            for(int i = 0; i < n; i++) { a[i] = nl(); } 
            return a;
        }
        int [][] nim(int n)
        {
            int mat[][]=new int[n][n];
            for(int i=0;i<n;i++)
            {
                for(int j=0;j<n;j++)
                {
                    mat[i][j]=ni();
                }
            }
            return mat;
        }
        long [][] nlm(int n)
        {
            long mat[][]=new long[n][n];
            for(int i=0;i<n;i++)
            {
                for(int j=0;j<n;j++)
                {
                    mat[i][j]=nl();
                }
            }
            return mat;
        }
        
     
     
     
     
        
        char[] ns(int n) { 
            char c[] = new char[n]; 
            int i, b = skip(); 
            for(i = 0; i < n; i++) { 
                if(isSpaceChar(b)) { break; } 
                c[i] = (char)b; b = readByte(); 
            } return i == n ? c : Arrays.copyOf(c,i);
        }
        void piarr(int arr[])
        {
            for(int i=0;i<arr.length;i++)
            {
                o.print(arr[i]+" ");
     
            }
            o.println();
        }
        void plarr(long arr[])
        {
            for(int i=0;i<arr.length;i++)
            {
                o.print(arr[i]+" ");
     
            }
            o.println();
        }
        
        void pimat(int mat[][])
        {
            for(int i=0;i<mat.length;i++)
            {
                for(int j=0;j<mat[0].length;j++)
                {
                    o.print(mat[i][j]+" ");
                }
                o.println();
            }
        }
        void plmat(long mat[][])
        {
            for(int i=0;i<mat.length;i++)
            {
                for(int j=0;j<mat[0].length;j++)
                {
                    o.print(mat[i][j]+" ");
                }
                o.println();
            }
     
        }
       static class DJset
{
    int n;
    ty1 arr[];
    class ty1
    {
        int rank;
        int par;
        ty1(int p,int r)
        {
            par=p;
            rank=r;
        }
    }
    DJset(int nu)
    {
        n=nu;
        arr=new ty1[n];
        for(int i=0;i<n;i++)
        {
            arr[i]=new ty1(i,1);
        }

    }
    int find(int x)
    {
        if(arr[x].par!=x)
        {
            arr[x].par=find(arr[x].par);
        }
        return arr[x].par;
    }
    void union(int x,int y)
    {
        x=find(x);
        y=find(y);
        if(x!=y)
        {
            if(arr[x].rank<arr[y].rank)
            {
                arr[x].par=y;
            }
            else if(arr[y].rank<arr[x].rank)
            {
                arr[y].par=x;
            }
            else
            {
                arr[x].rank++;
                arr[y].par=x;

            }
        }
    }
    public String toString()
    {
        String res="";
        for(int i=0;i<n;i++)
        {
            res+=(arr[i].par+" ");
        }
        
        return res;
    }
    public int countsets()
    {
        int res=0;
        for(int i=0;i<n;i++)
        {
            if(arr[i].par==i)
            {
                res++;
            }
        }
        return res;
    }

    

    }
    
     
     
     
     
        //////////////////////////////////// template finished //////////////////////////////////////
     
     
     
    }