#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<cassert>
using namespace std;

const int N = 1000;
int n,m,arga,argb;

int main()
{
	scanf("%d%d%d%d",&n,&m,&arga,&argb);
	for(int i=1; i<=n; i++)
	{
		for(int j=1; j<=m; j++)
		{
			printf("%d",(i<=argb)^(j<=arga));
		} puts("");
	}
	return 0;
}