#include <iostream>
#include <string>
using namespace std;
int main() {
    int H, W, A, B;
    cin >> H >> W >> A >> B;
    int t[] = {B, H - B};
    for (int i = 0; i < 2; i++) {
        for (int j = 0; j < t[i]; j++) {
            cout << string(A, i + '0') + string(W - A, 1 - i + '0') << endl;
        }
    }
}
