#include <bits/stdc++.h>

using namespace std;

int main(){
    int h,w,a,b;
    cin>>h>>w>>a>>b;
    
    if(min(a,b)==0){
        if(a==0){
            if(w==1){
                for (int i = 0; i < b; ++i) {
                    cout<<0<<endl;
                }
                for (int j = b; j < h; ++j) {
                    cout<<1<<endl;
                }
            }
            else{
                for (int i = 0; i < h; ++i) {
                    for (int j = 0; j < w; ++j) {
                        if(i<b)cout<<1;
                        else cout<<0;
                    }
                    cout<<endl;
                }
            }
        }
        else{
            if(h==1){
                for (int i = 0; i < a; ++i) {
                    cout<<0;
                }
                for (int j = a; j < w; ++j) {
                    cout<<1;
                }
            }
            else{
                for (int i = 0; i < h; ++i) {
                    for (int j = 0; j < w; ++j) {
                        if(j<a)cout<<1;
                        else cout<<0;
                    }
                    cout<<endl;
                }
            }

        }
        return 0;
    }
    vector<vector<int>> ans(h,vector<int>(w,0));
    for (int i = 0; i < a; ++i) {
        for (int j = 0; j < b; ++j) {
            ans[i][j]=1;
        }
    }
    for (int i = a; i < h; ++i) {
        for (int j = b; j < w; ++j) {
            ans[i][j]=1;
        }
    }
    for (int i = 0; i < h; ++i) {
        for (int j = 0; j < w; ++j) {
            cout<<ans[i][j];
        }
        cout<<endl;
    }
    return 0;
}