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

typedef pair<int, int> pii;
typedef long long ll;
typedef vector<int> vi;

#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fi first
#define se second
#define rep(i,n) rep2(i,0,n)
#define rep2(i,m,n) for(int i=m;i<(n);i++)
#define ALL(c) (c).begin(),(c).end()
#define dump(x) cout << #x << " = " << (x) << endl
constexpr ll TEN(int n) { return (n == 0) ? 1 : 10 * TEN(n-1); }

template<class T, class U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
	os<<"("<<p.first<<","<<p.second<<")";
	return os;
}

template<class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
	os<<"{";
	rep(i, v.size()) {
		if (i) os<<",";
		os<<v[i];
	}
	os<<"}";
	return os;
}

const ll MOD = 1000000007;
const int MX = 2e6;

ll inv[MX], fact[MX], ifact[MX];

void init() {
    inv[1] = 1;
    for (int i = 2; i < MX; ++i) {
        inv[i] = inv[MOD % i] * (MOD - MOD / i) % MOD;
    }
    fact[0] = ifact[0] = 1;
    for (int i = 1; i < MX; ++i) {
        fact[i] = fact[i-1] * i % MOD;
        ifact[i] = ifact[i-1] * inv[i] % MOD;
    }
}

ll comb(int n, int r) {
    if (n < 0 || r < 0 || r > n) return 0;
    return fact[n] * ifact[r] % MOD * ifact[n - r] % MOD;
}

int main() {
	int N, M; ll D1, D2;
	cin >> N >> M >> D1 >> D2;
	--M;

	if ((N - 1) * D1 > M) {
		puts("0");
		return 0;
	}

	init();

	M -= (N - 1) * D1;

	ll D = D2 - D1;

	vector<ll> way(N + 1);

	for (int i = N-1; i >= 0; --i) {
		if (i * (D + 1) > M) {
			continue;
		}
		int m = M - i * (D + 1);
		way[i] = comb(m + N, N) * comb(N-1, i) % MOD;
		way[i] -= way[i+1];
		if (way[i] < 0) way[i] += MOD; 
	}
	cout << way[0] << endl;

	return 0;
}