#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, a, b) for (int i = (a); i < (b); i++)
 
int main() {
    int h, w, a, b;
    cin >> h >> w >> a >> b;
    rep(i, 0, h) {
        rep(j, 0, w) cout << ((b <= i) ^ (a <= j));
        cout << endl;
    }
    return 0;
}