def powmod(n,pow,mod):
    val = 1
    while pow > 0:
        if pow & 1:
            val = (val * n) % mod
        pow = pow >> 1
        n = (n * n) % mod
    return val

n, m, x, y = map(int, input().split())
if (n < x) | (n < y):
    print(0)
    exit()
p = 10 ** 9 + 7
kaijo = [1 for i in range(n+m//2+2)]
invkaijo = [1 for i in range(n+m//2+2)]
for i in range(1,n+m//2+2):
    kaijo[i] = kaijo[i-1] * i % p
    invkaijo[i] = powmod(kaijo[i],p-2,p)

pmnum = [m // 4 for i in range(4)]
for i in range(m%4+1):
    pmnum[i] += 1

xans = [0 for i in range(n+1)]
yans = [0 for i in range(n+1)]

if x >= 0:
    if pmnum[2] >= 1:
        for i in range((n-x)//2+1):
            xans[x+i*2] = kaijo[x+i+pmnum[0]-1] * invkaijo[x+i] % p * invkaijo[pmnum[0]-1] % p
            xans[x+i*2] = xans[x+i*2] * kaijo[i+pmnum[2]-1] % p * invkaijo[i] % p * invkaijo[pmnum[2]-1] % p
    else:
        xans[x] = 1
else:
    x = -x
    if pmnum[2] >= 1:
        for i in range((n-x)//2+1):
            xans[x+i*2] = kaijo[x+i+pmnum[2]-1] * invkaijo[x+i] % p * invkaijo[pmnum[2]-1] % p
            xans[x+i*2] = xans[x+i*2] * kaijo[i+pmnum[0]-1] % p * invkaijo[i] % p * invkaijo[pmnum[0]-1] % p

if pmnum[1] >= 1:
    if y >= 0:
        if pmnum[3] >= 1:
            for i in range((n-y)//2+1):
                yans[y+i*2] = kaijo[y+i+pmnum[1]-1] * invkaijo[y+i] % p * invkaijo[pmnum[1]-1] % p
                yans[y+i*2] = yans[y+i*2] * kaijo[i+pmnum[3]-1] % p * invkaijo[i] % p * invkaijo[pmnum[3]-1] % p
        else:
            yans[y] = 1
    else:
        y = -y
        if pmnum[3] >= 1:
            for i in range((n-y)//2+1):
                yans[y+i*2] = kaijo[y+i+pmnum[3]-1] * invkaijo[y+i] % p * invkaijo[pmnum[3]-1] % p
                yans[y+i*2] = yans[y+i*2] * kaijo[i+pmnum[1]-1] % p * invkaijo[i] % p * invkaijo[pmnum[1]-1] % p
else:
    if y == 0:
        yans[0] = 1

ans = 0
for i in range(n+1):
    ans = (ans + xans[i] * yans[n-i] % p) % p

print("{}".format(ans))