#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define trav(a, x) for (auto& a : (x))
#define all(x) x.begin(), x.end() // sort(all(x))
#define sz(x) (int)(x).size()
#define mp(x, y) make_pair((x), (y))

typedef long long ll;

typedef double T;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> tiii;

typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef vector<T> vt;
typedef vector<vt> vvt;
typedef vector<pii> vpi;
typedef vector<pii> vpl;
typedef vector<vpi> graph;
typedef complex<T> Pt;
typedef pair<Pt, Pt> Line;

const ll MOD = 1000; // 998244353;
const T EPS = 1e-10;
const int INF = 1e9 + 1;

/* Mod Library */

struct Mod {
    ll x;
    Mod (ll x = 0) : x(x) {}
    Mod operator+(Mod b) { return Mod((x + b.x)%MOD); }
    Mod operator-(Mod b) { return Mod((x - b.x + MOD)%MOD); }
    Mod operator*(Mod b) { return Mod((x * b.x)%MOD); }
    Mod operator/(Mod b) { return *this * inverse(b); }
    Mod operator%(Mod b) { return Mod(x % b.x); }

    static ll euclid(ll a, ll b, ll &x, ll &y) {
        if (b) {
            ll d = euclid(b, a%b, y, x);
            y -= a/b*x;
            return d;
        }
        x = 1; 
        y = 0;
        return a;
    }
    
    Mod inverse(Mod a) {
        ll x, y, g = euclid(a.x, MOD, x, y);
        assert(g == 1);
        return Mod((x + MOD)%MOD);
    }

    Mod operator^(ll e) {
        if (!e) return Mod(1);
        Mod r = *this^(e/2);
        r = r*r;
        return e&1 ? *this*r : r;
    }
};

/* Input Library */
template <typename A, typename B>
istream& operator>>(istream &in, pair<A, B> &p) {
    in >> p.first >> p.second;
    return in;
}

template <typename A, typename B>
ostream& operator<<(ostream &out, pair<A, B> &p) {
    out << p.first << " " << p.second;
    return out;
}

template <typename I>
istream& operator>>(istream &in, vector<I> &a) {
    trav(i, a) in >> i;
    return in;
}

template <typename I>
ostream& operator<<(ostream &out, vector<I> &a) {
    rep(i, 0, sz(a)) {
        if (i) out << " ";
        out << a[i];
    }
    return out;
}

void fast_io() {
    cin.sync_with_stdio(0);
    cin.tie(0);
    //cout.tie(0);
    cin.exceptions(cin.failbit);
} 

/* Solution */

void solve_test() {
    int h, w, a, b;
    cin >> h >> w >> a >> b;

    vi can_col(h*w+1, -1);
    rep(zcol, 0, w+1) {
        int z = zcol*b + (w - zcol)*(h - b);
        can_col[z] = zcol;
    }

    int zrow, zcol;
    for(zrow = 0; zrow < h; zrow++) {
        int z = zrow*a + (h - zrow)*(w - a);
        if (can_col[z] >= 0) {
            zcol = can_col[z];
            break;
        }
    }
    
    if (zrow == h) {
        cout << -1 << endl;
        return;
    }

    vvi ans(h, vi(w, 0));
    vi col_c(w, b);
    rep(i, 0, zcol) col_c[i] = h-b;
    rep(i, 0, h) {
        vpi idx(w);
        rep(j, 0, w) {
            idx[j].first = col_c[j];
            idx[j].second = j;
        }
        sort(all(idx), greater<pii>());
        int ones = (i >= zrow ? a : w-a);
        rep(j, 0, ones) {
            if (idx[j].first) {
                ans[i][idx[j].second] = 1;
                col_c[idx[j].second]--;
            } else {
                exit(1);
            }
        }
    }
    rep(j, 0, w) { 
        if (col_c[j]) {
            cout << -1 << endl;
            return;
        }
    }

    rep(i, 0, h) {
        rep(j, 0, w) {
            cout << ans[i][j];
        }
        cout << endl; 
    }
}

void setup() {

}

int main() {
    setup();
    srand(time(0));
    fast_io();
    int t = 1;
    // cin >> t;
    while (t--) {
        solve_test();
    }
}


Measured memory_bytes: 9088