#include<iostream>
#include<algorithm>
using namespace std;

int main() {
    int h,w,a,b;
    cin >> h >> w >> a >> b;
    for (int i=0;i<b;i++) cout << string(a,'1') + string(w-a,'0') << endl;
    for (int j=b;j<h;j++) cout << string(a,'0') + string(w-a,'1') << endl;
    return 0;
}