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

constexpr int mod = 1000000007;

long long fac[2000005], finv[2000005], inv[2000005];

void COMinit() {
    fac[0] = fac[1] = finv[0] = finv[1] = inv[1] = 1;
    for (int i = 2; i < 2000005; i++) {
        fac[i] = fac[i - 1] * i % mod;
        inv[i] = mod - inv[mod % i] * (mod / i) % mod;
        finv[i] = finv[i - 1] * inv[i] % mod;
    }
}

long long COM(int n, int k) {
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * (finv[k] * finv[n - k] % mod) % mod;
}

int main() {
    int A,B,X,Y;
    cin >> A >> B >> X >> Y;
    COMinit();
    long long ans = 0;
    int a = 1+B/4;
    int b = min(1,B)+(B-1)/4;
    int c = min(1,B-1)+(B-2)/4;
    int d = min(1,B-2)+(B-3)/4;
    if(A-abs(X)-abs(Y) < 0 || (A-abs(X)-abs(Y))%2 != 0) {
        cout << 0 << endl;
        return 0;
    }
    for(int i = abs(X); i+abs(Y) <= A; i += 2) {
        int e = (i-abs(X))/2,f = i-e;
        long long tmp = 1;
        if(X >= 0) {
            tmp *= COM(a+f-1,a-1);
            tmp *= COM(c+e-1,c-1);
            tmp %= mod;
        }
        else {
            tmp *= COM(c+f-1,c-1);
            tmp *= COM(a+e-1,a-1);
            tmp %= mod;
        }
        e = ((A-i)-abs(Y))/2,f = (A-i)-e;
        if(Y >= 0) {
            tmp *= COM(b+f-1,b-1);
            tmp %= mod;
            tmp *= COM(d+e-1,d-1);
            tmp %= mod;
        }
        else {
            tmp *= COM(d+f-1,d-1);
            tmp %= mod;
            tmp *= COM(b+e-1,b-1);
            tmp %= mod;
        }
        ans += tmp;
        ans %= mod;
    }
    cout << ans << endl;
}