#include "bits/stdc++.h"
#include "atcoder/all"
using namespace std;
using namespace atcoder;
using mint = modint1000000007;
const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
//const bool debug = false;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
// combination mod prime
// https://www.youtube.com/watch?v=8uowVvQ_-Mo&feature=youtu.be&t=1619
struct combination {
	vector<mint> fact, ifact;
	combination(int n) :fact(n + 1), ifact(n + 1) {
		assert(n < mod);
		fact[0] = 1;
		for (int i = 1; i <= n; ++i) fact[i] = fact[i - 1] * i;
		ifact[n] = fact[n].inv();
		for (int i = n; i >= 1; --i) ifact[i - 1] = ifact[i] * i;
	}
	mint operator()(int n, int k) {
		return com(n, k);
	}
	mint com(int n, int k) {
		//負の二項係数を考慮する場合にコメントアウトを外す
		//if (n < 0) return com(-n, k) * (k % 2 ? -1 : 1);
		if (k < 0 || k > n) return 0;
		return fact[n] * ifact[k] * ifact[n - k];
	}
	mint inv(int n, int k) {
		//if (n < 0) return inv(-n, k) * (k % 2 ? -1 : 1);
		if (k < 0 || k > n) return 0;
		return ifact[n] * fact[k] * fact[n - k];
	}
	mint p(int n, int k) {
		return fact[n] * ifact[n - k];
	}
}biom(2000005);

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int a, b, x, y; cin >> a >> b >> x >> y;
	mint ans = 0;
	vector<int>v(4);
	v[0] = 1;
	rep(j, b)v[(j + 1) % 4]++;
	rep(i, a + 1) {
		vector<int>c(4);
		c[0] = i;
		c[2] = c[0] - x;
		if (c[2] < 0)continue;
		if (0 != (y + a - c[0] - c[2]) % 2)continue;
		c[1] = (y + a - c[0] - c[2]) / 2;
		c[3] = c[1] - y;
		if (c[1] < 0)continue;
		if (c[2] < 0)continue;
		if (c[3] < 0)continue;
		//cout << c[0] << " " << c[1] << " " << c[2] << " " << c[3] << endl;
		mint anssub = 1;
		rep(j, 4) {
			//cout << c[j] << " " << v[j] << endl;
			if ((0 == v[j]) && (0 == c[j]))continue;
			if ((0 == v[j]) && (0 != c[j])) {
				anssub = 0;
				continue;
			}
			anssub *= biom(c[j] + v[j] - 1, c[j]);
		}
		ans += anssub;
	}
	cout << ans.val() << endl;
	return 0;
}