#include<bits/stdc++.h>
#include<random>
using namespace std;
#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
//#define vec vector<ll>
//#define mat vector<vector<ll> >
#define fi first
#define se second
#define double long double
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> pll;
//typedef long double ld;
typedef complex<double> Complex;
const ll INF=1e9+7;
const ll MOD=998244353;
const ll inf=INF*INF;
const ll mod=INF;
const ll MAX=2000010;
const double PI=acos(-1.0);
typedef vector<vector<ll> > mat;
typedef vector<ll> vec;

//Combination
long long extGCD(long long a,long long mod,long long &x,long long &y){
    if(mod==0){
        x=1;
        y=0;
        return a;
    }
    long long d=extGCD(mod,a%mod,y,x);
    y-=(a/mod)*x;
    return d;
}
long long invmod(long long a,long long mod){
    long long x,y;
    extGCD(a,mod,x,y);
    x%=mod;
    if(x<0)x+=mod;
    return x;
}
ll fac[MAX],finv[MAX],inv[MAX];
void combinit(){
    fac[0]=fac[1]=1;
    finv[0]=finv[1]=1;
    inv[1]=1;
    REP(i,2,MAX){
        fac[i]=fac[i-1]*i%mod;
        inv[i]=invmod(i,mod);
        finv[i]=finv[i-1]*inv[i]%mod;
    }
}
ll comb(ll n,ll k){
    if(n<k)return 0;
    if(n<0||k<0)return 0;
    return fac[n]*(finv[k]*finv[n-k]%mod)%mod;
}

void solve(){
    combinit();
    vector<ll>mo(4);
    ll a,b,x,y;cin>>a>>b>>x>>y;
    rep(i,b+1)mo[i%4]++;
    ll ans=0;
    REP(i,abs(x),a-abs(y)+1){
        if((i+x)%2)continue;
        ll q=comb(mo[0]-1+(i+x)/2,mo[0]-1);
        ll w=comb(mo[2]-1+(i-x)/2,mo[2]-1);
        if(mo[2]==0&&(i==x))w=1;
        if(mo[0]==0&&(-i==x))q=1;
        ll j=a-i;
        if((j+y)%2)continue;
        ll s=comb(mo[1]-1+(j+y)/2,mo[1]-1);
        ll d=comb(mo[3]-1+(j-y)/2,mo[3]-1);
        if(mo[3]==0&&(j==y))d=1;
        if(mo[1]==0&&(-j==y))s=1;
        ans=(ans+q*w%mod*s%mod*d%mod)%mod;
        //cout<<i<<' '<<q<<' '<<w<<' '<<s<<' '<<w<<endl;
    }
    if(ans<0)ans+=mod;
    cout<<ans<<endl;
}

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
}