/* -*- coding: utf-8 -*-
 *
 * 1683.cc:  No.1683 Robot Guidance - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 2000000;
const int MOD = 1000000007;

enum { XP, YP, XM, YM };

/* typedef */

typedef long long ll;

/* typedef */

typedef long long ll;

template<const int MOD>
struct MI {
  int v;
  MI(): v() {}
  MI(int _v): v(_v % MOD) {}
  MI(ll _v): v(_v % MOD) {}

  MI operator+(const MI m) const { return MI((v + m.v) % MOD); }
  MI operator-(const MI m) const { return MI((v + MOD - m.v) % MOD); }
  MI operator*(const MI m) const { return MI((ll)v * m.v % MOD); }

  MI &operator+=(const MI m) { return (*this = *this + m); }
  MI &operator-=(const MI m) { return (*this = *this - m); }
  MI &operator*=(const MI m) { return (*this = *this * m); }

  MI pow(int n) const {  // a^n % MOD
    MI pm = 1, a = *this;
    while (n > 0) {
      if (n & 1) pm *= a;
      a *= a;
      n >>= 1;
    }
    return pm;
  }

  MI inv() const { return pow(MOD - 2); }
  MI operator/(const MI m) const { return *this * m.inv(); }
  MI &operator/=(const MI m) { return (*this = *this / m); }
};

typedef MI<MOD> mi;

/* global variables */

mi fs[MAX_N + 1], invfs[MAX_N + 1];
int rcs[4], dcs[4];

/* subroutines */

inline mi nck(int n, int k) {
  if (n < k || k < 0) return 0;
  return fs[n] * invfs[n - k] * invfs[k];
}

inline mi nhk(int n, int k) {
  mi c = nck(n + k - 1, k);
  //printf("nhk(%d, %d) = %d\n", n, k, c.v);
  return c;
}

void prepare_fracs(int n) {
  fs[0] = invfs[0] = 1;
  for (int i = 1; i <= n; i++) {
    fs[i] = fs[i - 1] * i;
    invfs[i] = fs[i].inv();
  }
}

/* main */

int main() {
  int a, b, x, y;
  scanf("%d%d%d%d", &a, &b, &x, &y);

  int r = a - (abs(x) + abs(y));
  if (r < 0 || (r & 1)) { puts("0"); return 0; }
  r /= 2;
  //printf("r=%d\n", r);

  if (x > 0) rcs[XP] = x;
  else if (x < 0) rcs[XM] = -x;
  if (y > 0) rcs[YP] = y;
  else if (y < 0) rcs[YM] = -y;

  int bq = (b + 1) / 4, br = (b + 1) % 4;
  for (int di = 0; di < 4; di++) {
    dcs[di] = bq + (di < br ? 1 : 0);
    if (dcs[di] == 0 && rcs[di] > 0) { puts("0"); return 0; }
  }
  //for (int di = 0; di < 4; di++) printf("%d ", dcs[di]); putchar('\n');

  prepare_fracs(a + b);

  mi sum = 0;
  for (int xc = 0; xc <= r; xc++) {
    rcs[XP] += xc, rcs[XM] += xc;
    rcs[YP] += r - xc, rcs[YM] += r - xc;

    mi p = 1;
    for (int di = 0; di < 4; di++) {
      if (dcs[di] == 0) {
	if (rcs[di] > 0) p = 0;
      }
      else
	p *= nhk(dcs[di], rcs[di]);
    }

    sum += p;
    
    rcs[XP] -= xc, rcs[XM] -= xc;
    rcs[YP] -= r - xc, rcs[YM] -= r - xc;
  }

  printf("%d\n", sum.v);
  return 0;
}