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 Fortran (gfortran v4.8.4) (judge verdict: Runtime Error)

! 2019.9.21 
! A
! Error --> 9999
! Correct(H /= 1) --> 8888
! Correct(H = 1) --> 7777
! Correct(W = 1) --> 6666
      program answer
      implicit none
      integer :: H, W, A, B  !input number
      double precision :: Hd, Wd, Ad, Bd
      integer(8) :: i,j
      integer :: mod_j
      integer,allocatable,dimension(:,:) :: ans
      intrinsic dble,mod
! read input number
      read(*,*) H, W, A, B
! H + A > W
      allocate(ans(H,W))
!
      ans = 0
!
      Hd=dble(H)
      Wd=dble(W)
      Ad=dble(A)
      Bd=dble(B)
! B > H/2
      if( Bd .gt. Hd/2.0d0) goto 9999
! H = 1
      if( H .eq. 1) goto 7777
! A > W/2
      if( Ad .gt. Wd/2.0d0) goto 9999
! W = 1
      if( W .eq. 1) goto 6666
! B = 0(H /= 1 & W /= 1)
      if( B .eq. 0) then
        if( W .eq. A) then
          goto 8888
        else
          goto 9999
        end if
! B /= 0(H /= 1 & W /= 1)
      else
        if( Hd*Ad/Bd .eq. Wd) then
          goto 8888
        else
          goto 9999
        end if
      end if
! Output(6666)
6666  do j=1,B
        ans(1,j) = 1
      end do
      do j=1,H
        write(*,'(I1)') ans(1,j)
      end do
      stop
! Output(7777)
7777  do i=1,A
        ans(1,i) = 1
      end do
      write(*,'(1000I1)') (ans(1,j),j=1,W)
      stop
! Output(8888)
8888  do i=1,H
        do j=A*i,A*(i+1)-1
          mod_j = mod(j,W)
          if( mod_j == 0) mod_j = W
          ans(i,mod_j) = 1
        end do
      end do
      do i=1,H
        write(*,'(1000I1)') (ans(i,j),j=1,W)
      end do
      stop
! Error(9999)
9999  write(*,*) 'No'
      stop
      end program answer