#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll=long long;
using Graph=vector<vector<int>>;
#define MAX 2000005
#define MOD 1000000007
//#define MOD 998244353
#define INF 1000000000
//#define INF 1000000000000000000

ll fac[MAX],finv[MAX],inv[MAX];

void COMinit(){
  fac[0]=fac[1]=1;
  finv[0]=finv[1]=1;
  inv[1]=1;
  for(int i=2;i<MAX;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;
  }
}

ll 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;
  if(abs(X)+abs(Y)>A){
    cout<<0<<'\n';
    return 0;
  }else if((abs(X)+abs(Y))%2!=A%2){
    cout<<0<<'\n';
    return 0;
  }

  COMinit();

  ll ans=0;
  for(int x=abs(X);x<=A-abs(Y);x+=2){
    int y=A-x;
    int x_plus=1;
    int y_plus=0;
    int x_minus=0;
    int y_minus=0;
    if(B%4==0){
      x_plus+=B/4;
      y_plus+=B/4;
      x_minus+=B/4;
      y_minus+=B/4;
    }else if(B%4==1){
      x_plus+=B/4;
      y_plus+=B/4+1;
      x_minus+=B/4;
      y_minus+=B/4;
    }else if(B%4==2){
      x_plus+=B/4;
      y_plus+=B/4+1;
      x_minus+=B/4+1;
      y_minus+=B/4;
    }else{
      x_plus+=B/4;
      y_plus+=B/4+1;
      x_minus+=B/4+1;
      y_minus+=B/4+1;
    }

    ll ret=1;
    if(X>0){
      if(X+(x-X)/2>0){
        ret*=COM(X+(x-X)/2+x_plus-1,x_plus-1);
        ret%=MOD;
      }
      if((x-X)/2>0){
        ret*=COM((x-X)/2+x_minus-1,x_minus-1);
        ret%=MOD;
      }
    }else{
      X=-X;
      if(X+(x-X)/2>0){
        ret*=COM(X+(x-X)/2+x_minus-1,x_minus-1);
        ret%=MOD;
      }
      if((x-X)/2>0){
        ret*=COM((x-X)/2+x_plus-1,x_plus-1);
        ret%=MOD;
      }
    }
    if(Y>0){
      if(Y+(y-Y)/2>0){
        ret*=COM(Y+(y-Y)/2+y_plus-1,y_plus-1);
        ret%=MOD;
      }
      if((y-Y)/2>0){
        ret*=COM((y-Y)/2+y_minus-1,y_minus-1);
        ret%=MOD;
      }
    }else{
      Y=-Y;
      if(Y+(y-Y)/2>0){
        ret*=COM(Y+(y-Y)/2+y_minus-1,y_minus-1);
        ret%=MOD;
      }
      if((y-Y)/2>0){
        ret*=COM((y-Y)/2+y_plus-1,y_plus-1);
        ret%=MOD;
      }
    }
    ans+=ret;
    ans%=MOD;
  }
  cout<<ans<<'\n';
}