#include <bits/stdc++.h>
using namespace std;
 
#define fi first
#define se second
#define pb push_back
using vi = vector <int>;
using ll = long long;
using pii = pair <int, int>;
//~ const ll mod = 998244353;
const ll mod = 1e9 + 7;
ll qpow(ll a, ll b, ll m = mod) { ll r = 1, t = a;
	for(; b; b /= 2) { if(b & 1) r = r * t % m; t = t * t % m; } return r; }

const int N = 2e6 + 11;
ll inv[N], fac[N], ifac[N];
ll binom(int n, int m) {
	if(n < m || m < 0) return 0; // n >= 0
	return fac[n] * ifac[m] % mod * ifac[n - m] % mod;
}

ll f(int m, int n) {
	return binom(m + n, n);
}

int main() {
	inv[1] = fac[0] = ifac[0] = 1;
	for(int i = 2; i < N; i ++)
		inv[i] = (mod - mod / i) * inv[mod % i] % mod;
	for(int i = 1; i < N; i ++) {
		fac[i] = i * fac[i - 1] % mod;
		ifac[i] = inv[i] * ifac[i - 1] % mod;
	}
	ios :: sync_with_stdio(false);
	
	int n; cin >> n;
	ll m, d1, d2; cin >> m >> d1 >> d2;
	
	m -= (n - 1) * d1; m --;
	int d = d2 - d1;
	
	ll ans = 0;
	if(m >= 0) {
		ans = f(m, n);
		for(int i = 1; i < n && m - i * (d + 1) >= 0; i ++) {
			int sgn = ((i & 1) ? -1 : 1);
			ans += sgn * binom(n - 1, i) * f(m - i * (d + 1), n);
			ans %= mod;
		}
	}
	
	ans %= mod;
	if(ans < 0) ans += mod;
	cout << ans << '\n';
}