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.omg.CORBA.INTERNAL;

import java.io. *;
import java.util.*;
import static java.lang.Math.*;
public class Main {

    static final FastReader sc = new FastReader(System.in);
    static final PrintWriter pw = new PrintWriter(System.out);

    static int visited[];
    static ArrayList<ArrayList<Integer>> adjlist;
    static class edge implements  Comparator<edge>{
        int dest;
        int cost;

        public edge(int dest, int cost) {
            this.dest = dest;
            this.cost = cost;
        }

        @Override
        public int compare(edge o1, edge o2) {
            return o1.cost-o2.cost;
        }
    }

    static int dist[];
    static int nodesinSubtree[];
    static int color[];
    static ArrayList<Integer> leaves;
    static ArrayList<PriorityQueue<Integer>> apq;

    static class Graph {
        int V;
        ArrayList<ArrayList<edge>> adj;
        PriorityQueue<edge> pq;
        boolean visited[];

        public Graph(int V) {
            this.V = V;
            adj = new ArrayList<>(V);
            pq = new PriorityQueue<>(V, new edge(-1, -1));
            dist = new int[V];
            visited = new boolean[V];
            for (int i = 0; i < V; i++) {
                dist[i] = Integer.MAX_VALUE;
                adj.add(i, new ArrayList<>());
            }
        }

        void addedge(int u, int v, int w) {
            adj.get(u).add(new edge(v, w));
            adj.get(v).add(new edge(u, w));
        }

        void rDfs(int src, int e) {
            if(adj.get(src).size()==0){
                leaves.add(src);
            }

            for (int i = 0; i < adj.get(src).size(); i++) {
                if (adj.get(src).get(i).dest == e) {
                    continue;
                }
                rDfs(adj.get(src).get(i).dest, src);
            }
        }

        PriorityQueue<Integer> Dfs(int src, int e, PriorityQueue<Integer> pq) {
            if(adj.get(src).size()==0){
                if(src!=0 && !pq.isEmpty()){
                    pq.remove(adj.get(src).get(e).cost);
                }
            }

            for (int i = 0; i < adj.get(src).size(); i++) {
                if (adj.get(src).get(i).dest == e) {
                    continue;
                }
                if (adj.get(src).get(i).dest == 1) {
                    pq.add(adj.get(src).get(i).cost);
                    return pq;
                }
                pq.add(adj.get(src).get(i).cost);
                Dfs(adj.get(src).get(i).dest, src, pq);
            }

            return pq;

        }



/*
        void dijkstra(int src){
            for(int i=0; i<V; i++){
                dist[i] = Integer.MAX_VALUE;
            }
            dist[src] = 0;
            pq.add(new edge(src,0));
            while (!pq.isEmpty()){
                int u = pq.poll().dest;
                for(int i=0; i<adj.get(u).size(); i++){
                    int v = adj.get(u).get(i).dest;
                    int w = adj.get(u).get(i).cost;
                    if(dist[u]+w<=dist[v]){
                        dist[v] = dist[u] + w;
                        pq.add(new edge(v,dist[v]));
                    }
                }
            }

        }


    }

 */
    }



    static  int I[];
    static  int  L[];
    static void LIS(int n, int arr[]){
        I = new int[n+1];
        L = new int[n];
        I[0] = Integer.MIN_VALUE;
        for(int i=1;i<=n; i++){
            I[i] = Integer.MAX_VALUE;
        }

        int lisLength = 1;

        for(int i=n-1; i>=0; i--) {
            int low = 1;
            int high = lisLength;
            int mid = 0;
            while (low < high) {
                mid = (low + high) >> 1;
                if (I[mid] <= arr[i]) {
                    high = mid;
                } else {
                    low = mid + 1;
                }
            }

            I[high] = arr[i];
            L[i] = high;
            if(lisLength<=high){
                lisLength++;
            }
        }
    }

    public static long gcd(long a, long b)
    {
        if (a == 0)
            return b;

        return gcd(b%a, a);
    }

    public static long lcm(long a, long b)
    {
        return (a*b)/gcd(a, b);
    }

    static long nCr(long n, long r)
    {
        return fact(n) / (fact(r) * fact(n - r));
    }

    // Returns factorial of n
    static long fact(long n)
    {
        long res = 1;
        for (int i = 2; i <= n; i++)
            res = (res * i)%MOD;
        return res;
    }


    static int MOD = 1000000007;
    static int power(int x, int y, int p)
    {

        // Initialize result
        int res = 1;

        // Update x if it is more than or
        // equal to p
        x = x % p;

        while (y > 0)
        {

            // If y is odd, multiply x
            // with result
            if (y % 2 == 1)
                res = (res * x) % p;

            // y must be even now
            y = y >> 1; // y = y/2
            x = (x * x) % p;
        }

        return res;
    }

    // Returns n^(-1) mod p
    static int modInverse(int n, int p)
    {
        return power(n, p-2, p);
    }

    static int nCrModPFermat(int n, int r,
                             int p)
    {

        if (r == 0)
            return 1;


        int[] fac = new int[n+1];
        fac[0] = 1;

        for (int i = 1 ;i <= n; i++)
            fac[i] = fac[i-1] * i % p;

        return (fac[n]* modInverse(fac[r], p)
                % p * modInverse(fac[n-r], p)
                % p) % p;
    }

    static int[] phi;

    static void generatePhi(int n){
        phi = new int[n+1];

        for(int i = 0; i<=n; i++){
            phi[i] = i;
        }

        for(int i=2; i<=n; i++){
            if(phi[i]==i){
                for(int j= i; j<=n; j+=i){
                    phi[j] -= (phi[j]/i);
                }
            }
        }
    }

    static int gcdCount(int n, int d){
        return phi[n/d];
    }

    static boolean prime[];
    static int smallestFactor[];

    static void sieveOfEratosthenes(int n)
    {
        prime = new boolean[n+1];
        smallestFactor = new int[n+1];

        smallestFactor[1] = 1;
        for(int i=2;i<n;i++) {
            prime[i] = true;
            smallestFactor[i] = i;
        }

        for(int p = 2; p*p <=n; p++)
        {
            if(prime[p])
            {
                smallestFactor[p] = p;
                for(int i = p*p; i <= n; i += p) {
                    prime[i] = false;
                    smallestFactor[i] = min(p,smallestFactor[i]);
                }
            }
        }

    }

    static double Logx(double n, int x){
        return log(n)/log(x);
    }

    static boolean isPrime(long n){
        if(n<2){
            return false;
        }
        for(int i = 2; i*i<=n; i++){
            if(n%i==0){
                return false;
            }
        }
        return true;
    }

    static int sumOfDigits(int n){
        int digitSum = 0;
        while (n>0){
            digitSum+=n%10;
            n/=10;
        }
        return digitSum;
    }


    static boolean checkSum(PriorityQueue<Integer> pq, long s){
        long sum = 0;
        while (!pq.isEmpty()){
            sum+= pq.poll();
        }
        if(sum>s){
            return false;
        }

        return true;

    }

    static class Point{
        int x;
        int y;

        public Point(int x, int y) {
            this.x = x;
            this.y = y;
        }

        public Point(Point p) {
            this.x = p.x;
            this.y = p.y;
        }

    }

    static int hx[] = {-1,1,0,0,};
    static int hy[] = {0,0,1,-1};

    public static void main(String[] args) {

            int n = sc.nextInt();
            int m = sc.nextInt();
            int sx = sc.nextInt();
            int sy = sc.nextInt();

            boolean visited[][] = new boolean[n+1][m+1];

        while (sy >= 1) {
            if (visited[sx][sy]) {
                sy--;
                continue;
            }
            pw.println(sx + " " + sy);
            visited[sx][sy] = true;
            sy--;
        }

        sy = 1;

        while (sy <= m) {
            if (visited[sx][sy]) {
                sy++;
                continue;
            }
            pw.println(sx + " " + sy);
            visited[sx][sy] = true;
            sy++;
        }
        sy = m;

            for(int i = sx+1; i<=n; i++) {
                if (sy== m) {
                    while (sy >= 1) {
                        if (visited[i][sy]) {
                            sy--;
                            continue;
                        }
                        pw.println(i + " " + sy);
                        visited[i][sy] = true;
                        sy--;
                    }

                    sy = 1;
                } else {
                    while (sy <= m) {
                        if (visited[i][sy]) {
                            sy++;
                            continue;
                        }
                        pw.println(i + " " + sy);
                        visited[i][sy] = true;
                        sy++;
                    }
                    sy = m;
                }
            }

        for(int i = sx-1; i>=1; i--){
            if(sy==m) {
                while (sy >= 1) {
                    if (visited[i][sy]) {
                        sy--;
                        continue;
                    }
                    pw.println(i + " " + sy);
                    visited[i][sy] = true;
                    sy--;
                }
                sy = 1;
            }else {
                while (sy <= m) {
                    if (visited[i][sy]) {
                        sy++;
                        continue;
                    }
                    pw.println(i + " " + sy);
                    visited[i][sy] = true;
                    sy++;
                }
                sy = m;
            }
        }



        pw.flush();

    }

    static void debug(Object...obj) {
        System.err.println(Arrays.deepToString(obj));
    }

    static class FastReader {
        InputStream is;
        private byte[] inbuf = new byte[1024];
        private int lenbuf = 0, ptrbuf = 0;

        public FastReader(InputStream is) {
            this.is = is;
        }

        public int readByte(){
            if(lenbuf == -1)throw new InputMismatchException();
            if(ptrbuf >= lenbuf){
                ptrbuf = 0;
                try {
                    lenbuf = is.read(inbuf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if(lenbuf <= 0)
                    return -1;
            }
            return inbuf[ptrbuf++];
        }
        public boolean isSpaceChar(int c) {
            return !(c >= 33 && c <= 126);
        }
        public int skip() {
            int b;
            while ((b = readByte()) != -1 && isSpaceChar(b)) ;
            return b;
        }
        public String next(){
            int b = skip();
            StringBuilder sb = new StringBuilder();
            while(!(isSpaceChar(b))) {
                sb.appendCodePoint(b);
                b = readByte();
            }
            return sb.toString();
        }
        public String nextLine(){
            int b = readByte();
            StringBuilder sb = new StringBuilder();
            while(b != '\n' || b != '\r'){
                sb.appendCodePoint(b);
            }
            return sb.toString();
        }
        public int nextInt() {
            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 << 3) + (num << 1) + (b - '0');
                } else {
                    return minus ? -num : num;
                }
                b = readByte();
            }
        }
        public long nextLong() {
            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 << 3) + (num << 1) + (b - '0');
                } else {
                    return minus ? -num : num;
                }
                b = readByte();
            }
        }
        public double nextDouble() {
            return Double.parseDouble(next());
        }
        public char[] next(int n){
            char[] buf = new char[n];
            int b = skip(), p = 0;
            while (p < n && !(isSpaceChar(b))) {
                buf[p++] = (char) b;
                b = readByte();
            }
            return n == p ? buf : Arrays.copyOf(buf, p);
        }
        public char nextChar () {
            return (char) skip();
        }
    }
}