#include <cassert>
#include <iostream>
#include <vector>
#include <atcoder/modint>
using namespace std;

// atcoder::static_modint<P>, P: prime number
template <typename modint> struct acl_fac {
    std::vector<modint> facs, facinvs;
    acl_fac(int N) {
        assert(-1 <= N and N < modint::mod());
        facs.resize(N + 1, 1);
        for (int i = 1; i <= N; i++) facs[i] = facs[i - 1] * i;
        facinvs.assign(N + 1, facs.back().inv());
        for (int i = N; i > 0; i--) facinvs[i - 1] = facinvs[i] * i;
    }
    modint ncr(int n, int r) const {
        if (n < 0 or r < 0 or n < r) return 0;
        return facs[n] * facinvs[r] * facinvs[n - r];
    }
    modint operator[](int i) const { return facs[i]; }
    modint finv(int i) const { return facinvs[i]; }
};
using mint = atcoder::modint1000000007;

int main() {
    int A, B, X, Y;
    cin >> A >> B >> X >> Y;
    acl_fac<mint> fac(A + B + X + Y);
    mint ret = 0;
    int nxplus = (B + 4) / 4;
    int nyplus = (B + 3) / 4;
    int nxminus = (B + 2) / 4;
    int nyminus = (B + 1) / 4;
    for (int xplus = 0; xplus <= A; xplus++) {
        int xminus = xplus - X;
        int rem = A - xplus - xminus;
        int yplus = (rem + Y) / 2;
        int yminus = (rem - Y) / 2;
        if (xminus < 0 or yplus < 0 or yminus < 0 or yplus - yminus != Y) continue;
        if (xplus + xminus + yplus + yminus != A) continue;
        if (!nyplus and yplus) continue;
        if (!nxminus and xminus) continue;
        if (!nyminus and yminus) continue;
        mint tmp = 1;
        if (xplus) tmp *= fac.ncr(nxplus - 1 + xplus, xplus);
        if (yplus) tmp *= fac.ncr(nyplus - 1 + yplus, yplus);
        if (xminus) tmp *= fac.ncr(nxminus - 1 + xminus, xminus);
        if (yminus) tmp *= fac.ncr(nyminus - 1 + yminus, yminus);
        ret += tmp;
    }
    cout << ret.val() << '\n';
}