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{
   public static void main(String[] args) throws IOException
   {
      FastScanner sc = new FastScanner();
      int N = sc.nextInt();//numrows
      int M = sc.nextInt();//numcols
      int Sx = sc.nextInt();
      int Sy = sc.nextInt();
      
      //first row
      System.out.println(Sx + " " + Sy);
      for(int y = 1; y <= M; y++){
         if(y != Sy){
            System.out.println(Sx + " " + y);
         }
      }
      
      int starty = M;
      //rows above
      for(int x = Sx-1; x > 0; x--){
         System.out.println(x + " " + starty);
         for(int y = 1; y <= M; y++){
            if(y != starty){
               System.out.println(x + " " + y);
            }
         }
         if(starty != M){
            starty = M;
         }
         else{
            starty--;
         }
      }
      
      //rows below
      for(int x = Sx+1; x <= N; x++){
         System.out.println(x + " " + starty);
         for(int y = 1; y <= M; y++){
            if(y != starty){
               System.out.println(x + " " + y);
            }
         }
         if(starty != M){
            starty = M;
         }
         else{
            starty--;
         }
      }
   }
   
   
   
   
   static class FastScanner {
      private int BS = 1 << 16;
      private char NC = (char) 0;
      private byte[] buf = new byte[BS];
      private int bId = 0, size = 0;
      private char c = NC;
      private double cnt = 1;
      private BufferedInputStream in;
   
      public FastScanner() {
         in = new BufferedInputStream(System.in, BS);
      }
   
      public FastScanner(String s) {
         try {
            in = new BufferedInputStream(new FileInputStream(new File(s)), BS);
         } catch (Exception e) {
            in = new BufferedInputStream(System.in, BS);
         }
      }
   
      private char getChar() {
         while (bId == size) {
            try {
               size = in.read(buf);
            } catch (Exception e) {
               return NC;
            }
            if (size == -1) 
               return NC;
            bId = 0;
         }
         return (char) buf[bId++];
      }
   
      public int nextInt() {
         return (int) nextLong();
      }
   
      public int[] nextInts(int N) {
         int[] res = new int[N];
         for (int i = 0; i < N; i++) {
            res[i] = (int) nextLong();
         }
         return res;
      }
   
      public long[] nextLongs(int N) {
         long[] res = new long[N];
         for (int i = 0; i < N; i++) {
            res[i] = nextLong();
         }
         return res;
      }
   
      public long nextLong() {
         cnt = 1;
         boolean neg = false;
         if (c == NC) c = getChar();
         for (; (c < '0' || c > '9'); c = getChar()) {
            if (c == '-') neg = true;
         }
         long res = 0;
         for (; c >= '0' && c <= '9'; c = getChar()) {
            res = (res << 3) + (res << 1) + c - '0';
            cnt *= 10;
         }
         return neg ? -res : res;
      }
   
      public double nextDouble() {
         double cur = nextLong();
         return c != '.' ? cur : cur + nextLong() / cnt;
      }
   
      public double[] nextDoubles(int N) {
         double[] res = new double[N];
         for (int i = 0; i < N; i++) {
            res[i] = nextDouble();
         }
         return res;
      }
   
      public String next() {
         StringBuilder res = new StringBuilder();
         while (c <= 32) c = getChar();
         while (c > 32) {
            res.append(c);
            c = getChar();
         }
         return res.toString();
      }
   
      public String nextLine() {
         StringBuilder res = new StringBuilder();
         while (c <= 32) c = getChar();
         while (c != '\n') {
            res.append(c);
            c = getChar();
         }
         return res.toString();
      }
   
      public boolean hasNext() {
         if (c > 32) 
            return true;
         while (true) {
            c = getChar();
            if (c == NC) 
               return false;
            else if (c > 32) 
               return true;
         }
      }
   }
 
   static void ASSERT(boolean assertion, String message) {
      if (!assertion) throw new AssertionError(message);
   }

}