#include <bits/stdc++.h>
using namespace std;
#define all(a)a.begin(),a.end()
using ll=long long;
const int INF = 1<<30;
const ll INFll =1LL<<62;
const int mod= int(1e9)+7;
//const int mod=998244353;
using P = pair<int,int>;
using Pl= pair<ll,ll>;
using ld=long double;
using V=vector<int>;
using Vl=vector<ll>;
using VV=vector<vector<int>>;
using VVl=vector<vector<ll>>;

// modint: mod 計算を int を扱うように扱える構造体
template<int MOD> struct Fp {
    long long val;
    constexpr Fp(long long v = 0) noexcept : val(v % MOD) {
        if (val < 0) val += MOD;
    }
    constexpr int getmod() { return MOD; }
    constexpr Fp operator - () const noexcept {
        return val ? MOD - val : 0;
    }
    constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; }
    constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; }
    constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; }
    constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; }
    constexpr Fp& operator += (const Fp& r) noexcept {
        val += r.val;
        if (val >= MOD) val -= MOD;
        return *this;
    }
    constexpr Fp& operator -= (const Fp& r) noexcept {
        val -= r.val;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr Fp& operator *= (const Fp& r) noexcept {
        val = val * r.val % MOD;
        return *this;
    }
    constexpr Fp& operator /= (const Fp& r) noexcept {
        long long a = r.val, b = MOD, u = 1, v = 0;
        while (b) {
            long long t = a / b;
            a -= t * b; swap(a, b);
            u -= t * v; swap(u, v);
        }
        val = val * u % MOD;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr bool operator == (const Fp& r) const noexcept {
        return this->val == r.val;
    }
    constexpr bool operator != (const Fp& r) const noexcept {
        return this->val != r.val;
    }
    friend constexpr ostream& operator << (ostream &os, const Fp<MOD>& x) noexcept {
        return os << x.val;
    }
    friend constexpr Fp<MOD> modpow(const Fp<MOD> &a, long long n) noexcept {
        if (n == 0) return 1;
        auto t = modpow(a, n / 2);
        t = t * t;
        if (n & 1) t = t * a;
        return t;
    }
};
using mint = Fp<mod>;

const int MAX = 1001001;
long long fac[MAX], finv[MAX], inv[MAX];

// テーブルを作る前処理
void COMinit() {
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    inv[1] = 1;
    for (int i = 2; i < MAX; i++){
        fac[i] = fac[i - 1] * i % mod;
        inv[i] = mod - inv[mod%i] * (mod / i) % mod;
        finv[i] = finv[i - 1] * inv[i] % mod;
    }
}

// 二項係数計算
long long COM(int n, int k){
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * (finv[k] * finv[n - k] % mod) % mod;
}

 ll nPr(int n, int r) {
    if (n < 0 || r < 0 || n < r) return 0;
    return fac[n] * finv[n - r] % mod;
}


int main(){
    COMinit();
    ll n,m,l,r;cin >>n>>m>>l>>r;
    vector<mint>P(r+1,0);//(1-x^m)/(1-x)^(n+1)
    // /(1-x)^(n+1)
    for (int i = 0; i <=r; ++i) {
        P[i]=COM(n+i,i);
    }
    //*(1-x^m)
    auto np=P;
    for (int i =m; i <=r; ++i) {
        P[i]-=np[i-m];
    }
    vector<mint>Q(r+1,0);//sum x^mk(1-x^k)n-m
    for (ll k =1; k <=r; ++k) {
        for (ll j =k*m; j<=min(k*n,r) ;j+=k) {
            ll i=(j-k*m)/k;
            if(i%2==0) {
                Q[j] += COM(n - m, i);
            }
            else {
                Q[j]-=COM(n - m, i);
            }
        }
    }
    mint R=0;
    for (int i = 0; i <=r; ++i) {
        R+=P[i]*Q[r-i];
    }
    mint L=0;
    for (int i = 0; i <=l-1; ++i) {
        L+=P[i]*Q[l-1-i];
    }
    mint UR=COM(n+r,r);
    mint UL=COM(n+l-1,l-1);
    R=UR-R*COM(n,m);
    L=UL-L*COM(n,m);
    cout <<R-L<<endl;
}

Measured memory_bytes: 33884