#include <bits/stdc++.h>
using namespace std;
#define DEBUG_MODE
#define endl '\n'
#ifdef DEBUG_MODE
#define DEBUG(X) debug_func(X, #X)
#define DEBUG_ENDL endl << flush
#define DEBUG_SEPARATOR_LINE cout<<"=================\n"
#else
#define DEBUG(X) 0
#define DEBUG_ENDL 0
#define DEBUG_SEPARATOR_LINE 0
#endif
#define ALL(V) (V).begin(), (V).end()
#define ALLR(V) (V).rbegin(), (V).rend()
#define DEBUG_ENDL_S(S) ((S).size() ? "\n" : "") << flush;
template <typename T> using V = vector<T>;
template <typename T> using VV = V<V<T>>;
template <typename T, typename U> using P = pair<T, U>;
using ll = int64_t;
using PLL = P<ll, ll>;
template <typename T> const T& var_min(const T &t) { return t; }
template <typename T> const T& var_max(const T &t) { return t; }
template <typename Head, typename... Tail> const Head& var_min(const Head &head, const Tail&... tail) { return min(head, var_min(tail...)); }
template <typename Head, typename... Tail> const Head& var_max(const Head &head, const Tail&... tail) { return max(head, var_max(tail...)); }
template <typename T, typename... Tail> void chmin(T &t, const Tail&... tail) { t = var_min(t, tail...); }
template <typename T, typename... Tail> void chmax(T &t, const Tail&... tail) { t = var_max(t, tail...); }
void debug_func_preffix(const string &s) { if(s.size()) cout << s << " = "; }
template <typename T>
void debug_func(const T &t, const string &s = "") {
    debug_func_preffix(s);
    cout << t << DEBUG_ENDL_S(s);
}
template <typename T, typename U>
void debug_func(const P<T, U> &p, const string &s = "") {
    debug_func_preffix(s);
    cout << "(";
    debug_func(p.first);
    cout << ", ";
    debug_func(p.second);
    cout << ")" << DEBUG_ENDL_S(s);
}
template <typename T>
void debug_func(const V<T> &v, const string &s = "") {
    for(ll i = 0; i < v.size(); i++) {
        string t = s + "[" + to_string(i) + "]";
        debug_func(v[i], t);
    }
}

void init_io() {
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(30);
}

const ll MOD = 1e9 + 7;

class Combination {
private:
    template <typename T> using V = vector<ll>;
    ll N;
    ll MOD;
    V<ll> factv, rfactv;

public:
    /*
     * MOD must be a prime number.
     */
    Combination(ll N, ll MOD)
        : N(N), 
          MOD(MOD),
          factv(N + 1, 1),
          rfactv(N + 1)
    {
        for(ll i = 1; i <= N; i++) {
            factv[i] = factv[i - 1] * i % MOD;
        }
        for(ll i = 0; i <= N; i++) {
            rfactv[i] = pow(factv[i], MOD - 2);
        }
    }

    ll fact(ll n) {
        return factv[n];
    }

    ll rfact(ll n) {
        return rfactv[n];
    }

    ll pow(ll a, ll b) {
        return b ? (b & 1 ? a : 1) * pow(a * a % MOD, b / 2) % MOD : 1;
    }

    ll comb(ll n, ll k) {
        return factv[n] * rfactv[n - k] % MOD * rfactv[k] % MOD;
    }
};

Combination comb(1e6 + 3e5 + 10, MOD);
ll N, M, D1, D2;
ll distr;

ll calc(ll n) {
    if(n > N - 1) return 0;
    ll rest = distr - (D2 - D1 + 1) * n;
    if(rest < 0) return 0;
    ll ret = comb.comb(rest + N, N) * comb.comb(N - 1, n) % MOD;
    ((ret -= calc(n + 1)) += MOD) %= MOD;
    return ret;
}

int main() {
    init_io();
    cin >> N >> M >> D1 >> D2;
    distr = M - 1 - D1 * (N - 1);
    if(distr < 0) {
        cout << 0 << endl;
        return 0;
    }
    cout << calc(0) << endl;
    return 0;
}