//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx")
//#undef LOCAL
#include <bits/stdc++.h>

using namespace std;
using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;
constexpr ll TEN(int n) { return (n == 0) ? 1 : 10 * TEN(n - 1); }
template <class T> using V = vector<T>;
template <class T> using VV = V<V<T>>;

#ifdef LOCAL
struct PrettyOS {
    ostream& os;
    bool first;
    template <class T> auto operator<<(T&& x) {
        if (!first) os << ", ";
        first = false;
        os << x;
        return *this;
    }
};
template <class... T> void dbg0(T&&... t) {
    (PrettyOS{cerr, true} << ... << t);
}
#define dbg(...)                                            \
    do {                                                    \
        cerr << __LINE__ << " : " << #__VA_ARGS__ << " = "; \
        dbg0(__VA_ARGS__);                                  \
        cerr << endl;                                       \
    } while (false);
#else
#define dbg(...)
#endif

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

template <class T> ostream& operator<<(ostream& os, const V<T>& v) {
    os << "[";
    for (auto d : v) os << d << ", ";
    return os << "]";
}


template <uint MD> struct ModInt {
    using M = ModInt;
    const static M G;
    uint v;
    ModInt(ll _v = 0) { set_v(_v % MD + MD); }
    M& set_v(uint _v) {
        v = (_v < MD) ? _v : _v - MD;
        return *this;
    }
    explicit operator bool() const { return v != 0; }
    M operator-() const { return M() - *this; }
    M operator+(const M& r) const { return M().set_v(v + r.v); }
    M operator-(const M& r) const { return M().set_v(v + MD - r.v); }
    M operator*(const M& r) const { return M().set_v(ull(v) * r.v % MD); }
    M operator/(const M& r) const { return *this * r.inv(); }
    M& operator+=(const M& r) { return *this = *this + r; }
    M& operator-=(const M& r) { return *this = *this - r; }
    M& operator*=(const M& r) { return *this = *this * r; }
    M& operator/=(const M& r) { return *this = *this / r; }
    bool operator==(const M& r) const { return v == r.v; }
    M pow(ll n) const {
        M x = *this, r = 1;
        while (n) {
            if (n & 1) r *= x;
            x *= x;
            n >>= 1;
        }
        return r;
    }
    M inv() const { return pow(MD - 2); }
    friend ostream& operator<<(ostream& os, const M& r) { return os << r.v; }
};
using Mint = ModInt<TEN(9) + 7>;
// template<> const Mint Mint::G = Mint(3);

const int MN = 1'000'000;

Mint fact[MN], iFac[MN];

void first() {
    fact[0] = Mint(1);
    for (int i = 1; i < MN; i++) fact[i] = fact[i - 1] * Mint(i);
    iFac[MN - 1] = fact[MN - 1].inv();
    for (int i = MN - 1; i >= 1; i--) {
        iFac[i - 1] = iFac[i] * Mint(i);
    }
    assert(fact[2345] * iFac[2345] == Mint(1));
}
Mint C(int n, int k) {
    if (n < k || k < 0) return Mint(0);
    return fact[n] * iFac[k] * iFac[n - k];
}

Mint solve2(int r, int n, int m, int x) {
    Mint ans = 0;
    for (int k = 0; k <= m; k++) {
        int r2 = r - k * x;
        if (r2 < 0) break;
        Mint buf = C(m, k) * C(r2 + n, n);
        if (k % 2 == 0) ans += buf;
        else ans -= buf;
    }        
    return ans;
}

Mint solve(int r, int n, int m) {
    Mint ans = C(r + n, n);
    for (int x = 1; x <= MN; x++) {
        int r2 = r - x * m;
        if (r2 < 0) break;
        ans -= C(n, m) * (solve2(r2, n, n - m, x) - solve2(r2 - m, n, n - m, x));
    }
    return ans;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
    first();
    int n, m, l, r;
    cin >> n >> m >> l >> r;
    Mint ans = 0;
    ans += solve(r, n, m);
    dbg(ans);
    ans -= solve(l - 1, n, m);
    dbg(ans);
    cout << ans << endl;
    return 0;
}


Measured memory_bytes: 8064