#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

inline int rd() {
    int x = 0;
    bool f = 0;
    char c = getchar();
    for (; !isdigit(c); c = getchar()) f |= (c == '-');
    for (; isdigit(c); c = getchar()) x = x * 10 + (c ^ 48);
    return f ? -x : x;
}

#define fr first
#define sc second
#define mp make_pair
#define pb push_back
#define pii pair<int, int>

#define N 2000007
#define mod 1000000007

int fac[N], ifac[N];
 
inline int fpow(int x, int t = mod - 2) {
    int res = 1;
    for (; t; t >>= 1, x = 1ll * x * x % mod)
        if (t & 1) res = 1ll * res * x % mod;
    return res;
}
 
inline void init() {
    fac[0] = ifac[0] = 1;
    for (int i = 1; i < N; ++i) fac[i] = 1ll * fac[i - 1] * i % mod;
    ifac[N - 1] = fpow(fac[N - 1], mod - 2);
    for (int i = N - 2; i; --i) ifac[i] = 1ll * ifac[i + 1] * (i + 1) % mod;
}
 
inline int C(int n, int m) {
    if (n < m) return 0;
    return 1ll * fac[n] * ifac[m] % mod * ifac[n - m] % mod;
}

int main() {
    init();
    int a = rd(), b = rd(), c = rd(), d = rd();
    int n = a, g = b, i = c, e = d;
    if (g >= 2 * n) {printf("%d\n", 2 * n); return 0;}

    int dn = fpow(C(2 * n, g)), ans = 0;

    for (int k = 0; k <= n; ++k) {
        n = a, g = b, i = c, e = d;
        int sig = g - 2 * k;
        if (sig < 0 || sig > n - k) continue;
        int p = 1ll * C(n, k) * C(n - k, sig) % mod * fpow(2, sig) % mod * dn % mod;
        int toth = g;
        int ept = n - k - sig;
        
        bool fl = 0;
        if (e <= sig) {
            toth += e;
            sig -= e;
        } else {
            toth += sig; e -= sig; sig = 0;
            int w = min(e / 2, ept);
            toth += w * 2; ept -= w; e -= w * 2;
            if (e && ept) {--ept; ++sig; fl = 1;}
        }


        if (i <= ept) toth += i;
        else {
            i = max(0, i - ept);
            if (i && fl) ++toth;
            i = max(0, i - sig);
            toth += max(ept - i, 0);
        }
        ans = (ans + 1ll * p * toth) % mod;
    }
    printf("%d\n", ans);

    return 0;
}