#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
const long nPrime = 1000000007;
//const long nPrime = 998244353;
typedef long long ll;
long Inverse(const long &n){
    if (n % nPrime == 0){
        return 0;
    }
    long a = n, b = nPrime, u = 1, v = 0;
    while (b > 0) {
        long t = a / b;
        a -= t * b;
        swap(a, b);
        u -= t * v;
        swap(u, v);
    }
    u %= nPrime;
    if (u < 0){
        u += nPrime;
    }
    return u;    
}
int main() {
    vector<long> viTable(2000001,1), viInv(2000001,1);
    for(long i = 1; i <= 2000000; i++){
        viTable[i] = (viTable[i-1] * i) % nPrime;
        viInv[i] = Inverse(viTable[i]);
    }
    
    long a,b,x,y;
    cin >> a >> b >> x >> y;
    if(((a+x+y)&1) == 1){
        cout << 0 << endl;
        return 0;
    }
    
    long i1 = (b+4)/4;
    long i2 = (b+2)/4;
    long i3 = (b+3)/4;
    long i4 = (b+1)/4;
    
    long nAns = 0;
    for(long s = 0; s <= a; s++){
        long t = s-x;
        long u = (a-2*s+x+y)/2;
        long v = u-y;
        if(t < 0 || u < 0 || v < 0){
            continue;
        }
        if((i2 == 0 && t > 0) ||(i3 == 0 && u > 0) ||(i4 == 0 && v > 0) ){
            continue;
        }
        
        long iThis = 1;
        iThis *= viTable[s+i1-1];
        iThis %= nPrime;
        iThis *= viInv[s];
        iThis %= nPrime;
        iThis *= viInv[i1-1];
        iThis %= nPrime;
        if(i2 > 0){
            iThis *= viTable[t+i2-1];
            iThis %= nPrime;
            iThis *= viInv[t];
            iThis %= nPrime;
            iThis *= viInv[i2-1];
            iThis %= nPrime;
        }
        if(i3 > 0){
            iThis *= viTable[u+i3-1];
            iThis %= nPrime;
            iThis *= viInv[u];
            iThis %= nPrime;
            iThis *= viInv[i3-1];
            iThis %= nPrime;
        }
        if(i4 > 0){
            iThis *= viTable[v+i4-1];
            iThis %= nPrime;
            iThis *= viInv[v];
            iThis %= nPrime;
            iThis *= viInv[i4-1];
            iThis %= nPrime;
        }
        nAns += iThis;
        nAns %= nPrime;
    }
    
    cout << nAns << endl;
    return 0;
}