#!/usr/bin/ python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import numpy as np

MOD = 10 ** 9 + 7


def cumprod(A, MOD=MOD):
    L = len(A)
    Lsq = int(L**.5 + 1)
    A = np.resize(A, Lsq**2).reshape(Lsq, Lsq)
    for n in range(1, Lsq):
        A[:, n] *= A[:, n - 1]
        A[:, n] %= MOD
    for n in range(1, Lsq):
        A[n] *= A[n - 1, -1]
        A[n] %= MOD
    return A.ravel()[:L]


def make_fact(U, MOD=MOD):
    x = np.arange(U, dtype=np.int64)
    x[0] = 1
    fact = cumprod(x, MOD)
    x = np.arange(U, 0, -1, dtype=np.int64)
    x[0] = pow(int(fact[-1]), MOD - 2, MOD)
    fact_inv = cumprod(x, MOD)[::-1]
    fact.flags.writeable = False
    fact_inv.flags.writeable = False
    return fact, fact_inv


N, M, D1, D2 = map(int, read().split())
M -= 1 + D1 * (N - 1)
if M < 0:
    print(0)
    exit()
n = D2 - D1 + 1

fact, fact_inv = make_fact(N + M + 10)
fact = fact.tolist()
fact_inv = fact_inv.tolist()

answer = 0
for i in range(N):
    j = M - n * i
    if j < 0:
        break
    x = fact[N - 1] * fact_inv[i] * fact_inv[N - 1 - i]
    y = fact[N + j] * fact_inv[N] * fact_inv[j]
    answer += x * y * pow(-1, i)

print(answer % MOD)