Problem:
Score : 300 points

Problem Statement

We have a square grid with H rows and W columns.
Snuke wants to write 0 or 1 in each of the squares.
Here, all of the following conditions have to be satisfied:

For every row, the smaller of the following is A: the number of 0s contained in the row, and the number of 1s contained in the row. (If these two numbers are equal, “the smaller” should be read as “either”.)

For every column, the smaller of the following is B: the number of 0s contained in the column, and the number of 1s contained in the column.

Determine if these conditions can be satisfied by writing 0 or 1 in each of the squares. If the answer is yes, show one way to fill the squares so that the conditions are satisfied.

Constraints

1 \leq H,W \leq 1000

0 \leq A

2 \times A \leq W

0 \leq B

2 \times B \leq H

All values in input are integers.

Input

Input is given from Standard Input in the following format:

H W A B

Output

If the conditions cannot be satisfied by writing 0 or 1 in each of the squares, print -1.

If the conditions can be satisfied, print one way to fill the squares so that the conditions are satisfied, in the following format:

s_{11}s_{12}\cdots s_{1W}
s_{21}s_{22}\cdots s_{2W}
\vdots
s_{H1}s_{H2}\cdots s_{HW}

Here s_{ij} is the digit written in the square at the i-th row from the top and the j-th column from the left in the grid.

If multiple solutions exist, printing any of them will be accepted.

Sample Input 1

3 3 1 1

Sample Output 1

100
010
001

Every row contains two 0s and one 1, so the first condition is satisfied.
Also, every column contains two 0s and one 1, so the second condition is satisfied.

Sample Input 2

1 5 2 0

Sample Output 2

01010

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

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

template <class T> using V = vector<T>;
template <class S, class T> using P = pair<S, T>;

using ll = long long;
using ull = unsigned long long;
using vll = V<ll>;
using vvll = V<vll>;
using vvvll = V<vvll>;
using pl = P<ll, ll>;
using vpl = V<pl>;
using vvpl = V<vpl>;
using vs = V<string>;
using qll = queue<ll>;
using qpl = queue<pl>;
using mapll = map<ll, ll>;
using setll = set<ll>;
using pqll = priority_queue<ll>;

#define int ll
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define pob pop_back()
#define pf push_front
#define pof pop_front()
#define sz size()
#define bgn begin()
#define en end()
#define emp empty()
#define fr front()
#define bk back()
#define res resize
#define tp top()
#define p_q priority_queue
#define inv inverse()

#define FOR(i,a,b) for(ll i=(a);i<=(ll)(b);i++)
#define rFOR(i,a,b) for(ll i=(b);i>=(ll)(a);i--)
#define REP(i,a) FOR((i),0,(ll)(a)-1)
#define REP0(i,a) FOR((i),0,(ll)(a))
#define REP1(i,a) FOR((i),1,(ll)(a))
#define rREP(i,a) rFOR((i),0,(ll)(a)-1)
#define rREP0(i,a) rFOR((i),0,(ll)(a))
#define rREP1(i,a) rFOR((i),1,(ll)(a))
#define IOTA(a,n) iota((a).bgn,(a).en,(n))
#define SORT(a) sort((a).bgn,(a).en)
#define rSORT(a) sort((a).rbegin(),(a).rend())
#define UNIQUE(a) (a).erase(unique((a).bgn,(a).en),(a).en)
#define BINS(a,b) binary_search((a).bgn,(a).en,(b))
#define LOWB(a,b) (lower_bound((a).bgn,(a).en,(b))-(a).bgn)
#define UPB(a,b) (upper_bound((a).bgn,(a).en,(b))-(a).bgn)
#define CNT(a,b) count((a).bgn,(a).en,b)
#define SUM(a) accumulate((a).bgn,(a).en,0)
#define REV(a) reverse((a).bgn,(a).en)
#define yn(a) cout <<((a)?"yes":"no")<<"\n";
#define Yn(a) cout <<((a)?"Yes":"No")<<"\n";
#define YN(a) cout <<((a)?"YES":"NO")<<"\n";
#define imp(a) cout <<((a)?"possible":"impossible")<<"\n";
#define Imp(a) cout <<((a)?"Possible":"Impossible")<<"\n";
#define IMP(a) cout <<((a)?"POSSIBLE":"IMPOSSIBLE")<<"\n";
#define dbg(a) cerr <<(#a)<<": "<<(a)<<"\n";
#define DigN2(a) ((llabs(a)==0)?(1):((ll)(log2(double(llabs(a))))+1))
#define DigN10(a) ((llabs(a)==0)?(1):((ll)(log10(double(llabs(a))))+1))
#define Dig2(a,b) (((a)>>(b))&1)
#define Dig10(a,b) (ll)(((a)/((ll)(pow(10.0,(double)(b)))))%10)
#define Pow2(a) ((ll)(1)<<(a))
#define Pow10(a) ((ll)(pow(10.0,double(a))))
#define powll(a,b) (ll)(pow((double)(a),(double)(b)))

#define li(...) ll __VA_ARGS__;Input(__VA_ARGS__);
#define si(...) string __VA_ARGS__;Input(__VA_ARGS__);
#define vli(size, ...) vll __VA_ARGS__;vInput(size,__VA_ARGS__);
#define vsi(size, ...) vs __VA_ARGS__;vInput(size,__VA_ARGS__);

const ll MOD = 1e9 + 7;
//const ll MOD = 998244353;
//const ll MOD = 924844033;
//const ll MOD = 9007199254740881;
const ll INF = 1LL << 60;//1.15e18
const double PI = acos(-1.0);
const string alp = "abcdefghijklmnopqrstuvwxyz";
const string ALP = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

void Input() {}
template <class Var, class... Args> void Input(Var& var, Args&... args) {
    cin >> var;
    Input(args...);
}

void vInit(ll size) {}
template <class T, class... Args> void vInit(ll size, V<T>& v, Args&... args) {
    v.res(size);
    vInit(size, args...);
}
void vInputNum(ll num) {}
template <class T, class... Args> void vInputNum(ll num, V<T>& v, Args&... args) {
    cin >> v[num];
    vInputNum(num, args...);
}
void vInput(ll size) {}
template <class... Args> void vInput(ll size, Args&... args) {
    vInit(size, args...);
    REP(i, size) vInputNum(i, args...);
}

template <class S, class T> ostream &operator<<(ostream &out, const P<S, T> &p) {
    return out << "[" << p.fi << ", " << p.se << "]";
}
 
template <class T> ostream &operator<<(ostream &out, V<T> &v) {
    if (v.emp) return out << "{}";
    else {
        auto itr = v.bgn;
        out << "{" << *itr;
        itr++;
        while (itr != v.en) {
            out << ", " << *itr;
            itr++;
        }
        out << "}";
        return out;
    }
}
 
template <class S, class T> ostream &operator<<(ostream &out, const map<S, T> &m) {
    if (m.emp) return out << "<[]>";
    else {
        auto itr = m.bgn;
        out << "< [" << (itr->fi) << ": " << (itr->se);
        itr++;
        while (itr != m.en) {
            out << "], [" << (itr->fi) << ": " << (itr->se);
            itr++;
        }
        out << "] >";
        return out;
    }
}
 
template <class T> ostream &operator<<(ostream &out, const set<T> &s) {
    if (s.emp) return out << "<>";
    else {
        auto itr = s.bgn;
        out << "<" << *itr;
        itr++;
        while (itr != s.en) {
            out << ", " << *itr;
            itr++;
        }
        out << ">";
        return out;
    }
}

ll gcd(ll a, ll b) { if (a < b) { a ^= b; b ^= a; a ^= b; } return b ? gcd(b, a%b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b)*b; }

struct UFT {

public:
    ll tsize;
    ll mode;
    vll par;
    vll rank;
    UFT() {}
    UFT(const UFT &uft) {}
    UFT(ll tsizeget, ll modeget = 0){
        tsize = tsizeget;
        mode = modeget;
        par.assign(tsize, -1);
        if (!mode) rank.res(tsize, 0);
    }
    ll root(ll x) {
        return par[x] < 0 ? x : par[x] = root(par[x]);
    }
    bool isRoot(ll x) {
        return x == root(x);
    }
    bool same(ll x, ll y) {
        return root(x) == root(y);
    }
    void merge(ll x, ll y) {
        x = root(x);
        y = root(y);
        if (x == y) return;
        if (mode) {
            par[x] += par[y];
            par[y] = x;
        }
        else {
            if (rank[x] < rank[y]) {
                par[y] += par[x];
                par[x] = y;
            }
            else {
                par[x] += par[y];
                par[y] = x;
                if (rank[x] == rank[y]) rank[x]++;
            }
        }
    }
    ll size(ll x) {
        return -par[root(x)];
    }
};

ll isP(ll n) {
    if (n <= 1) return 0;
    FOR(i, 2, (ll)sqrt(n) + 1) {
        if (n%i == 0) return 0;
    }
    return 1;
}

vvll CombMemo(3000, vll(3000, -1));

ll Comb(ll n, ll k) {
    if ((n < 0) || (k < 0)) return 0;
    if (CombMemo[n][k] == -1) {
        if (n < k) CombMemo[n][k] = 0;
        else {
            if (n == 0) CombMemo[n][k] = 1;
            else if (k == 0) CombMemo[n][k] = 1;
            else if (n == k) CombMemo[n][k] = 1;
            else CombMemo[n][k] = Comb(n - 1, k - 1) + Comb(n - 1, k);
        }
    }
    return CombMemo[n][k];
}

void Solve();

signed main() { 
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << setprecision(20) << fixed;
    Solve();
}

void Solve() {
  li(h,w,a,b);
  vvll v(1000,vll(1000,0));
  
  if(a>w/2||b>h/2) {
    cout << "No";
    return;
  }
  
  REP(i,a){
    REP(j,h){
      v[j][i]=1-v[j][i];
    }
  }
  REP(i,b){
    REP(j,w){
      v[i][j]=1-v[i][j];
    }
  }
  REP(i,h){
    REP(j,w){
      cout << v[i][j];
    }
    cout << endl;
  }
}