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 C# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;//list用
using System.Text;//StringBuilder用
using System.Collections;//ハッシュテーブル用
using System.Linq;

class Program
{
    //Hashtable ht = new Hashtable();
    static List<int> s = new List<int>();
    static List<int>[] sl;
    static decimal result;
    static int N,K;
    //Append(str ○○)関数で文字を追加していく



    static void Main()
    {
        //Modular mo = new Modular(0);//素数で割った余りを出せで使う。()内が初期値。★使い方：Modular型で宣言すると、その時点でのその素数で割った余りを保持する変数になる（powべき乗、Fac累乗、nCr組み合わせも関数として存在）
        //Node<> no = new Node<>();//UnionFind★Find関数で根っこの値を返す（根っこの値が一緒なら同グループ）、Unite関数で二つの木をくっつける
        //Permutation<> pe = new Permutation<>();//配列＆リストを並べ替えた場合の全ケースを出力★All関数でリスト形式で返す。
        //Treap<> tr = new Treap<>();//平衡二分木★Insert()関数で挿入、FindIndex()関数で該当する大きさの物が入るべき配列番号を返す。
        //PriorityQueue<int,int> pr = new PriorityQueue<int,int>();//優先度付キュー★Add(key,value)で格納、Dequeue()で取りだし。keyが小さいものから取り出す。
Read3();
      int H=s[0];
      int W=s[1];
      int A=s[2];
      int B=s[3];
      //成立する場合、等間隔の1:1斜めタスキになる。タスキが切れた次行で新タスキを０列からスタートさせて
      //一番下の行でもタスキの数が同数を維持できているかが勝負。
      
      //まず何個間隔になるかをW,Aの値から確定
      int kankaku;
      int start=0;
      kankaku=W/A;
      start=W%A;
int[,] check=new int[W,H];
      
      
      for(int j=0;j<W;j++){
      if(j%kankaku==start){check[j,0]=1;}
      }
      for(int i=1;i<H;i++){
        int tmp=check[W-1,i-1];
for(int j=W-2;j>=0;j--){check[j+1,i]=check[j,i-1];}
        check[0,i]=tmp;
      }
for(int j=0;j<W;j++){if(check[j,H-1]==1){result++;}}
      if(result==A){
        for(int i=0;i<H;i++){
          StringBuilder strresult= new StringBuilder("");
      for(int j=0;j<W;j++){strresult.Append(check[j,i]);}
              Console.WriteLine(strresult);
        }
      }else{
        Console.WriteLine("No"); 
      }
    }


    static void Read1()//1項
    {
        string tmp = Console.ReadLine();
        N = int.Parse(tmp);
    }

    static void Read2()//複数項（項目数Ｎ）
    {
        string[] tmp = Console.ReadLine().Split(' ');
        for (int i = 0; i < N; i++) { s.Add(int.Parse(tmp[i])); }
    }
    static void Read3()//1行複数項
    {
        string[] tmp = Console.ReadLine().Split(' ');
        for (int i = 0; i < tmp.Length; i++) { s.Add(int.Parse(tmp[i])); }
    }
    static void Read4()//NK１行
    {
        string[] tmp = Console.ReadLine().Split(' ');
        N = int.Parse(tmp[0]);
        K = int.Parse(tmp[1]);
    }
    static void Read5()//N行K項
    {
        sl = new List<int>[N];
        for (int i = 0; i < N; i++) {
            sl[i] = new List<int>();
            string[] tmp = Console.ReadLine().Split(' ');
            for (int j = 0; j < K; j++) {
                sl[i].Add(int.Parse(tmp[j]));
            }
        }

    }
}