#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
#define FOR(i,l,r) for(ll i=l;i<r;i++)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,l,r) for(ll i=r-1;i>=l;i--)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(x) x.begin(),x.end()
#define P pair<ll,ll>
#define F first
#define S second
#define BS(A,x) binary_search(ALL(A),x)
#define LB(A,x) (ll)(lower_bound(ALL(A),x)-A.begin())
#define UB(A,x) (ll)(upper_bound(ALL(A),x)-A.begin())
#define COU(A,x) UB(A,x)-LB(A,x)
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
using mint=modint1000000007;
signed main(){
  ll A,B,X,Y,c=1;cin>>A>>B>>X>>Y;vector<ll>p(4),q(4);p[0]=1;
  while(B){p[c]++;B--;c=(c+1)%4;}
  if((A+X+Y)%2){cout<<0<<endl;return 0;}mint ans=0;
  vector<mint>K(4000000,1);FOR(i,2,4000000)K[i]=K[i-1]*i;
  REP(i,A+1){
    q[0]=i;q[2]=i-X;q[1]=(A+X+Y)/2-i;q[3]=(A+X-Y)/2-i;
    if(min({q[1],q[2],q[3]})>=0){
      mint res=1;
      REP(j,4){if(!p[j]){if(q[j])res=0;}else res*=K[p[j]+q[j]-1]/K[p[j]-1]/K[q[j]];}
      ans+=res;
    }
  }
  cout<<ans.val()<<endl;
  return 0;
}