import sys
from operator import itemgetter
from collections import defaultdict, deque
import heapq
import bisect

stdin=sys.stdin
sys.setrecursionlimit(10 ** 8)

ip=lambda: int(sp())
fp=lambda: float(sp())
lp=lambda:list(map(int,stdin.readline().split()))
sp=lambda:stdin.readline().rstrip()
Yp=lambda:print('Yes')
Np=lambda:print('No')
inf = 1 << 60
eps = 1e-9
sortkey = itemgetter(0)
mod = 10 ** 9 + 7

class Comb():
    def __init__(self, N, mod):
        self.N = N
        self.mod = mod
        self.fa = self.fa_fainv()[0]
        self.fainv = self.fa_fainv()[1]

    def fa_fainv(self):
        fa = [1]
        for i in range(1, self.N + 1):
            fa.append(fa[-1] * i % self.mod)

        fainv = [pow(fa[-1],self.mod - 2,self.mod)]
        for i in range(1, self.N + 1)[::-1]:
            fainv.append(fainv[-1] * i % self.mod)
        fainv = fainv[::-1]

        return fa, fainv

    def calcu_comb(self, a, b):
        if b == 0:
            return 1
        return self.fa[a] * self.fainv[a - b] * self.fainv[b] % self.mod


###############################################################
comb = Comb(2 * 10 ** 6 + 5, mod)

A, B, X, Y = lp()
x = (B + 2) // 2
y = B + 1- x

xp = (x + 1) // 2
xm = x - xp

yp = (y + 1) // 2
ym = y - yp

ans = 0

for i in range(A + 1):
    x_move = i
    y_move = A - i
    if abs(X - x_move) % 2 != 0 or abs(Y - y_move) % 2 != 0 or x_move < abs(X) or y_move < abs(Y):
        continue
    now_xp = (x_move + X) // 2
    now_xm = x_move - now_xp

    now_yp = (y_move + Y) // 2
    now_ym = y_move - now_yp

    if now_xp > 0 and xp <= 0:
        continue
    if now_xm > 0 and xm <= 0:
        continue
    if now_yp > 0 and yp <= 0:
        continue
    if now_ym > 0 and ym < 0:
        continue

    p = comb.calcu_comb(now_xp + xp - 1,xp - 1)
    q = comb.calcu_comb(now_xm + xm - 1,xm - 1)
    r = comb.calcu_comb(now_yp + yp - 1,yp - 1)
    s = comb.calcu_comb(now_ym + ym - 1,ym - 1)
    res = p * q * r * s % mod
    ans += res
    ans %= mod

print(ans)