Problem:
Score : 300 points

Problem Statement

We have a square grid with H rows and W columns.
Snuke wants to write 0 or 1 in each of the squares.
Here, all of the following conditions have to be satisfied:

For every row, the smaller of the following is A: the number of 0s contained in the row, and the number of 1s contained in the row. (If these two numbers are equal, “the smaller” should be read as “either”.)

For every column, the smaller of the following is B: the number of 0s contained in the column, and the number of 1s contained in the column.

Determine if these conditions can be satisfied by writing 0 or 1 in each of the squares. If the answer is yes, show one way to fill the squares so that the conditions are satisfied.

Constraints

1 \leq H,W \leq 1000

0 \leq A

2 \times A \leq W

0 \leq B

2 \times B \leq H

All values in input are integers.

Input

Input is given from Standard Input in the following format:

H W A B

Output

If the conditions cannot be satisfied by writing 0 or 1 in each of the squares, print -1.

If the conditions can be satisfied, print one way to fill the squares so that the conditions are satisfied, in the following format:

s_{11}s_{12}\cdots s_{1W}
s_{21}s_{22}\cdots s_{2W}
\vdots
s_{H1}s_{H2}\cdots s_{HW}

Here s_{ij} is the digit written in the square at the i-th row from the top and the j-th column from the left in the grid.

If multiple solutions exist, printing any of them will be accepted.

Sample Input 1

3 3 1 1

Sample Output 1

100
010
001

Every row contains two 0s and one 1, so the first condition is satisfied.
Also, every column contains two 0s and one 1, so the second condition is satisfied.

Sample Input 2

1 5 2 0

Sample Output 2

01010

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.BufferedWriter;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author gaidash
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        A01Matrix solver = new A01Matrix();
        solver.solve(1, in, out);
        out.close();
    }

    static class A01Matrix {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int sizeI = in.nextInt();
            int sizeJ = in.nextInt();
            int smallJ = in.nextInt();
            int smallI = in.nextInt();

            if (smallI + smallJ == 0) {
                for (int i = 0; i < sizeI; i++) {
                    for (int j = 0; j < sizeJ; j++) {
                        out.print(0);
                    }
                    out.println();
                }
            }

            if (sizeI == 1) {
                int[] ret = new int[sizeJ];
                for (int i = 0; i < smallJ; i++) {
                    ret[i] = 1;
                }
                for (int val : ret) {
                    out.print(val);
                }
                out.println();
                return;
            }
            if (sizeJ == 1) {
                int[] ret = new int[sizeI];
                for (int i = 0; i < smallI; i++) {
                    ret[i] = 1;
                }
                for (int val : ret) {
                    out.println(val);
                }
                return;
            }

            if (smallI == 0 || smallJ == 0 || sizeJ % smallJ > 0 || sizeI % smallI > 0 || sizeJ / smallJ != sizeI / smallI) {
                out.println(-1);
                return;
            }

            int[][] ret = new int[sizeI][sizeJ];
            int col = 0;
            for (int startI = 0; startI + smallI <= sizeI; startI += smallI) {
                for (int i = startI; i < startI + smallI; i++) {
                    for (int j = col; j < col + smallJ; j++) {
                        ret[i][j] = 1;
                    }
                }
                col += smallJ;
            }

            for (int i = 0; i < sizeI; i++) {
                for (int j = 0; j < sizeJ; j++) {
                    out.print(ret[i][j]);
                }
                out.println();
            }
        }

    }

    static 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 println() {
            writer.println();
        }

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

        public void print(int i) {
            writer.print(i);
        }

        public void println(int i) {
            writer.println(i);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

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

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

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

        }

    }
}