#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
using uint = unsigned int;
using pcc = pair<char, char>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<double, double>;
using tuplis = array<ll, 3>;
template<class T> using pq = priority_queue<T, vector<T>, greater<T>>;
const ll LINF=0x1fffffffffffffff;
const ll MINF=0x7fffffffffff;
const int INF=0x3fffffff;
const int MOD=1000000007;
const int MODD=998244353;
const ld DINF=numeric_limits<ld>::infinity();
const ld EPS=1e-9;
const ld PI=3.1415926535897932;
const ll four[] = {0, 1, 0, -1, 0};
const ll eight[] = {0, 1, 1, 0, -1, -1, 1, -1, 0};
#define overload4(_1,_2,_3,_4,name,...) name
#define overload3(_1,_2,_3,name,...) name
#define rep1(n) for(ll i=0;i<n;++i)
#define rep2(i,n) for(ll i=0;i<n;++i)
#define rep3(i,a,b) for(ll i=a;i<b;++i)
#define rep4(i,a,b,c) for(ll i=a;i<b;i+=c)
#define rep(...) overload4(__VA_ARGS__,rep4,rep3,rep2,rep1)(__VA_ARGS__)
#define rrep1(n) for(ll i=(n)-1;i>=0;i--)
#define rrep2(i,n) for(ll i=(n)-1;i>=0;i--)
#define rrep3(i,a,b) for(ll i=(b)-1;i>=(a);i--)
#define rrep4(i,a,b,c) for(ll i=a+(b-a-1)/c*c;i>=a;i-=c)
#define rrep(...) overload4(__VA_ARGS__,rrep4,rrep3,rrep2,rrep1)(__VA_ARGS__)
#define each(i,...) for(auto&& i:__VA_ARGS__)
#define all1(i) begin(i),end(i)
#define all2(i,a) begin(i),begin(i)+a
#define all3(i,a,b) begin(i)+a,begin(i)+b
#define all(...) overload3(__VA_ARGS__,all3,all2,all1)(__VA_ARGS__)
#define rall1(i) (i).rbegin(),(i).rend()
#define rall2(i,k) (i).rbegin(),(i).rbegin()+k
#define rall3(i,a,b) (i).rbegin()+a,(i).rbegin()+b
#define rall(...) overload3(__VA_ARGS__,rall3,rall2,rall1)(__VA_ARGS__)
#define sum(...) accumulate(all(__VA_ARGS__),0LL)
#define dsum(...) accumulate(all(__VA_ARGS__),0.0L)
#define elif else if
#define unless(a) if(!(a))
#define mp make_pair
#define mt make_tuple
#define INT(...) int __VA_ARGS__;in(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;in(__VA_ARGS__)
#define ULL(...) ull __VA_ARGS__;in(__VA_ARGS__)
#define STR(...) string __VA_ARGS__;in(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__;in(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__;in(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__;in(__VA_ARGS__)
#define Sort(a) sort(all(a))
#define Rev(a) reverse(all(a))
#define Uniq(a) sort(all(a));a.erase(unique(all(a)),end(a))
#define vec(type,name,...) vector<type> name(__VA_ARGS__)
#define VEC(type,name,size) vector<type> name(size);in(name)
#define vv(type,name,h,...) vector<vector<type>>name(h,vector<type>(__VA_ARGS__))
#define VV(type,name,h,w) vector<vector<type>>name(h,vector<type>(w));in(name)
#define vvv(type,name,h,w,...) vector<vector<vector<type>>>name(h,vector<vector<type>>(w,vector<type>(__VA_ARGS__)))
template<class T> auto max(const T& a){ return *max_element(all(a)); }
template<class T> auto min(const T& a){ return *min_element(all(a)); }
ll gcd(ll a, ll b){ while(b){ ll c = b; b = a % b; a = c; } return a; }
ll lcm(ll a, ll b){ if(!a || !b) return 0; return a * b / gcd(a, b); }
ll intpow(ll a, ll b){ ll ans = 1; while(b){ if(b & 1) ans *= a; a *= a; b /= 2; } return ans; }
ll modpow(ll a, ll b, ll p){ ll ans = 1; while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; }
template<class T> bool chmin(T& a, const T& b){ if(a > b){ a = b; return 1; } return 0; }
template<class T> bool chmax(T& a, const T& b){ if(a < b){ a = b; return 1; } return 0; }
vector<pll> factor(ull x){ vector<pll> ans; for(ll i = 2; i * i <= x; i++) if(x % i == 0){ ans.push_back({i, 1}); while((x /= i) % i == 0) ans.back().second++; } if(x != 1) ans.push_back({x, 1}); return ans; }
vector<ll> divisor(ull x){ vector<ll> ans; for(ll i = 1; i * i <= x; i++) if(x % i == 0) ans.push_back(i); rrep(ans.size() - (ans.back() * ans.back() == x)) ans.push_back(x / ans[i]); return ans; }
template<class T> unordered_map<T, ll> press(vector<T>& a){ auto b = a; sort(all(b)); b.erase(unique(all(b)), b.end()); unordered_map<T,ll> ans; rep(b.size()) ans[b[i]] = i; each(i, a) i = ans[i]; return ans; }
template<class T> map<T, ll> press_map(vector<T>& a){ auto b = a; sort(all(b)); b.erase(unique(all(b)), b.end()); map<T,ll> ans; rep(b.size()) ans[b[i]] = i; each(i, a) i = ans[i]; return ans; }
int scan(){ return getchar(); }
void scan(int& a){ scanf("%d", &a); }
void scan(unsigned& a){ scanf("%u", &a); }
void scan(long& a){ scanf("%ld", &a); }
void scan(long long& a){ scanf("%lld", &a); }
void scan(unsigned long long& a){ scanf("%llu", &a); }
void scan(char& a){ do{ a = getchar(); }while(a == ' ' || a == '\n'); }
void scan(float& a){ scanf("%f", &a); }
void scan(double& a){ scanf("%lf", &a); }
void scan(long double& a){ scanf("%Lf", &a); }
void scan(vector<bool>& a){ for(unsigned i = 0; i < a.size(); i++){ int b; scan(b); a[i] = b; } }
void scan(char a[]){ scanf("%s", a); }
void scan(string& a){ cin >> a; }
template<class T> void scan(vector<T>&);
template<class T, size_t size> void scan(array<T, size>&);
template<class T, class L> void scan(pair<T, L>&);
template<class T, size_t size> void scan(T(&)[size]);
template<class T> void scan(vector<T>& a){ for(auto&& i : a) scan(i); }
template<class T> void scan(deque<T>& a){ for(auto&& i : a) scan(i); }
template<class T, size_t size> void scan(array<T, size>& a){ for(auto&& i : a) scan(i); }
template<class T, class L> void scan(pair<T, L>& p){ scan(p.first); scan(p.second); }
template<class T, size_t size> void scan(T (&a)[size]){ for(auto&& i : a) scan(i); }
template<class T> void scan(T& a){ cin >> a; }
void in(){}
template <class Head, class... Tail> void in(Head& head, Tail&... tail){ scan(head); in(tail...); }
void print(){ putchar(' '); }
void print(bool a){ printf("%d", a); }
void print(int a){ printf("%d", a); }
void print(unsigned a){ printf("%u", a); }
void print(long a){ printf("%ld", a); }
void print(long long a){ printf("%lld", a); }
void print(unsigned long long a){ printf("%llu", a); }
void print(char a){ printf("%c", a); }
void print(char a[]){ printf("%s", a); }
void print(const char a[]){ printf("%s", a); }
void print(float a){ printf("%.15f", a); }
void print(double a){ printf("%.15f", a); }
void print(long double a){ printf("%.15Lf", a); }
void print(const string& a){ for(auto&& i : a) print(i); }
template<class T> void print(const vector<T>&);
template<class T, size_t size> void print(const array<T, size>&);
template<class T, class L> void print(const pair<T, L>& p);
template<class T, size_t size> void print(const T (&)[size]);
template<class T> void print(const vector<T>& a){ if(a.empty()) return; print(a[0]); for(auto i = a.begin(); ++i != a.end(); ){ putchar(' '); print(*i); } }
template<class T> void print(const deque<T>& a){ if(a.empty()) return; print(a[0]); for(auto i = a.begin(); ++i != a.end(); ){ putchar(' '); print(*i); } }
template<class T, size_t size> void print(const array<T, size>& a){ print(a[0]); for(auto i = a.begin(); ++i != a.end(); ){ putchar(' '); print(*i); } }
template<class T, class L> void print(const pair<T, L>& p){ print(p.first); putchar(' '); print(p.second); }
template<class T, size_t size> void print(const T (&a)[size]){ print(a[0]); for(auto i = a; ++i != end(a); ){ putchar(' '); print(*i); } }
template<class T> void print(const T& a){ cout << a; }
int out(){ putchar('\n'); return 0; }
template<class T> int out(const T& t){ print(t); putchar('\n'); return 0; }
template<class Head, class... Tail> int out(const Head& head, const Tail&... tail){ print(head); putchar(' '); out(tail...); return 0; }
#ifdef DEBUG
void err(){ putchar('\n'); }
template<class T> void err(const T& t){ print(t); putchar('\n'); }
template<class Head, class... Tail> void err(const Head& head, const Tail&... tail){ print(head); putchar(' '); out(tail...); }
#else
template<class... T> void err(const T&...){}
#endif
int first(bool i = true){ return out(i?"first":"second"); }
int yes(bool i = true){ return out(i?"yes":"no"); }
int Yes(bool i = true){ return out(i?"Yes":"No"); }
int No(){ return out("No"); }
int YES(bool i = true){ return out(i?"YES":"NO"); }
int NO(){ return out("NO"); }
int Yay(bool i = true){ return out(i?"Yay!":":("); }
int possible(bool i = true){ return out(i?"possible":"impossible"); }
int Possible(bool i = true){ return out(i?"Possible":"Impossible"); }
int POSSIBLE(bool i = true){ return out(i?"POSSIBLE":"IMPOSSIBLE"); }
void Case(ll i){ printf("Case #%lld: ", i); }



namespace fft{
    const int maxBase = 21;
    const int maxN = 1 << maxBase;
    struct num{
        double x, y;
        num(){}
        num(double xx, double yy): x(xx), y(yy){}
        num(double alp): x(cos(alp)), y(sin(alp)){}
    };
    inline static constexpr int pw(int a){ return 1 << a; }
    inline num operator+(num a, num b){ return num(a.x + b.x, a.y + b.y); }
    inline num operator-(num a, num b){ return num(a.x - b.x, a.y - b.y); }
    inline num operator*(num a, num b){ return num(a.x * b.x - a.y * b.y, a.x * b.y + a.y * b.x); }
    inline num conj(num a){ return num(a.x, -a.y); }
    const double PI = acos(-1);
    num root[maxN];
    int rev[maxN];
    bool rootsPrepared = false;
    void prepRoots(){
        if(rootsPrepared) return;
        rootsPrepared = true;
        root[1] = num(1, 0);
        for(int k = 1; k < maxBase; ++k){
            num x(2 * PI / pw(k + 1));
            for(int i = pw(k - 1); i < pw(k); ++i){
                root[2 * i] = root[i];
                root[2 * i + 1] = root[i] * x;
            }
        }
    }
    int base, N;
    int lastRevN = -1;
    void prepRev(){
        if(lastRevN == N) return;
        lastRevN = N;
        rep(i, N) rev[i] = (rev[i >> 1] >> 1) + ((i & 1) << (base - 1));
    }
    void fft(num *a, num *f){
        rep(i, N) f[i] = a[rev[i]];
        for(int k = 1; k < N; k <<= 1) for(int i = 0; i < N; i += 2 * k) rep(j, k){
            num z = f[i + j + k] * root[j + k];
            f[i + j + k] = f[i + j] - z;
            f[i + j] = f[i + j] + z;
        }
    }
    num a[maxN], b[maxN], f[maxN], g[maxN];
    ll A[maxN], B[maxN], C[maxN];
    void _multMod(int mod){
        rep(i, N){
            int x = A[i] % mod;
            a[i] = num(x & (pw(15) - 1), x >> 15);
        }
        rep(i, N){
            int x = B[i] % mod;
            b[i] = num(x & (pw(15) - 1), x >> 15);
        }
        fft(a, f);
        fft(b, g);
        rep(i, N){
            int j = (N - i) & (N - 1);
            num a1 = (f[i] + conj(f[j])) * num(0.5, 0);
            num a2 = (f[i] - conj(f[j])) * num(0, -0.5);
            num b1 = (g[i] + conj(g[j])) * num(0.5 / N, 0);
            num b2 = (g[i] - conj(g[j])) * num(0, -0.5 / N);
            a[j] = a1 * b1 + a2 * b2 * num(0, 1);
            b[j] = a1 * b2 + a2 * b1;
        }
        fft(a, f);
        fft(b, g);
        rep(i, N){
            ll aa = f[i].x + 0.5;
            ll bb = g[i].x + 0.5;
            ll cc = f[i].y + 0.5;
            C[i] = (aa + bb % mod * pw(15) + cc % mod * pw(30)) % mod;
        }
    }
    void prepAB(int n1, int n2){
        base = 1;
        N = 2;
        while (N < n1 + n2) base++, N <<= 1;
        assert(base <= maxBase);
        
        for(int i = n1; i < N; ++i) A[i] = 0;
        for(int i = n2; i < N; ++i) B[i] = 0;
        
        prepRoots();
        prepRev();
    }
    void multMod(int n1, int n2, int mod){
        prepAB(n1, n2);
        _multMod(mod);
    }
}

const int mod = MOD;
struct FPS{
    using vi = vector<int>;
    vi v;
    FPS(){}
    FPS(const vi& vv){ v = vv; }
    int size() const { return static_cast<int>(v.size()); }
    FPS cut(int maxLen){
        if(maxLen < size()) v.resize(maxLen);
        return *this;
    }
    FPS norm(){
        while (size() > 1 && v.back() == 0) v.pop_back();
        return *this;
    }
    inline int& operator[](int i){ return v[i]; }
    inline const int& operator[](int i) const { return v[i]; }
    FPS operator+(const FPS& B) const {
        FPS C;
        C.v = vi(max(size(), B.size()));
        rep(i, C.size()){
            if(i < size()){
                C[i] += v[i];
                if(C[i] >= mod) C[i] -= mod;
            }
            if(i < B.size()){
                C[i] += B[i];
                if(C[i] >= mod) C[i] -= mod;
            }
        }
        return C.norm();
    }
    FPS operator-(const FPS& B) const {
        FPS C;
        C.v = vi(max(size(), B.size()));
        rep(i, C.size()){
            if(i < size()){
                C[i] += v[i];
                if(C[i] >= mod) C[i] -= mod;
            }
            if(i < B.size()){
                C[i] -= B[i];
                if(C[i] < 0) C[i] += mod;
            }
        }
        return C.norm();
    }
    FPS operator*(const FPS& B) const {
        FPS C;
        C.v = vi(size() + B.size() - 1);
        rep(i, size()) fft::A[i] = v.at(i);
        rep(i, B.size()) fft::B[i] = B[i];
        fft::multMod(size(), B.size(), mod);
        rep(i, C.size()) C[i] = fft::C[i];
        return C.norm();
    }
    FPS _cutPoly(int l, int r) const {
        FPS R;
        R.v.resize(r - l);
        for(int i = l; i < r; ++i) if(i < size()) R[i - l] = v[i];
        return R;
    };
    int _rev(int x, int m) const {
        if(x == 1) return 1;
        return (1 - _rev(m % x, x) * (ll)m) / x + m;
    };
    FPS inv(int n){ // returns A^-1 mod x^n
        assert(size() && v[0] != 0);
        cut(n);
        FPS R({_rev(v[0], mod)});
        for(int k = 1; k < n; k <<= 1){
            FPS A0 = _cutPoly(0, k);
            FPS A1 = _cutPoly(k, 2 * k);
            FPS H = A0 * R;
            H = H._cutPoly(k, 2 * k);
            FPS R1 = (((A1 * R).cut(k) + H) * (FPS({0}) - R)).cut(k);
            R.v.resize(2 * k);
            rep(i, k) R[i + k] = R1[i];
        }
        return R.cut(n).norm();
    }
    inline FPS rev() const {
        FPS f = *this;
        reverse(all(f.v));
        return f;
    };
    pair<FPS, FPS> divide(FPS B, FPS &B1){
        if(size() < B.size()) return {FPS({0}), *this};
        FPS q = (B1*rev()).cut(size() - B.size() + 1).rev();
        FPS r = *this - B * q;
        return {q, r};
    }
};
struct Modint{
    uint num = 0;
    constexpr Modint(){}
    constexpr Modint(const Modint &x) : num(x.num){}
    inline constexpr operator ll() const { return num; }
    inline constexpr Modint& operator+=(Modint x){ num += x.num; if(num >= mod) num -= mod; return *this; }
    inline constexpr Modint& operator++(){ if(num == mod - 1) num = 0; else num++; return *this; }
    inline constexpr Modint operator++(int){ Modint ans(*this); operator++(); return ans; }
    inline constexpr Modint operator- () const { return Modint(0) -= *this; }
    inline constexpr Modint operator- (Modint x) const { return Modint(*this) -= x; }
    inline constexpr Modint& operator-=(Modint x){ if(num < x.num) num += mod; num -= x.num; return *this; }
    inline constexpr Modint& operator--(){ if(num == 0) num = mod - 1; else num--; return *this; }
    inline constexpr Modint operator--(int){ Modint ans(*this); operator--(); return ans; }
    inline constexpr Modint& operator*=(Modint x){ num = ull(num) * x.num % mod; return *this; }
    inline constexpr Modint& operator/=(Modint x){ return operator*=(x.inv()); }
    template<class T> constexpr Modint(T x){
        using U = typename conditional<sizeof(T) >= 4, T, int>::type;
        U y = x; y %= U(mod); if(y < 0) y += mod; num = uint(y);
    }
    template<class T> inline constexpr Modint operator+(T x) const { return Modint(*this) += x; }
    template<class T> inline constexpr Modint& operator+=(T x){ x %= mod; if(x < 0) x += mod; num += x; if(num >= mod) num -= mod; return *this; }
    template<class T> inline constexpr Modint operator- (T x) const { return Modint(*this) -= x; }
    template<class T> inline constexpr Modint& operator-=(T x){ return operator-=(Modint(x)); }
    template<class T> inline constexpr Modint operator* (T x) const { return Modint(*this) *= x; }
    template<class T> inline constexpr Modint& operator*=(T x){ return operator*=(Modint(x)); }
    template<class T> inline constexpr Modint operator/ (T x) const { return Modint(*this) /= x; }
    template<class T> inline constexpr Modint& operator/=(T x){ return operator/=(Modint(x)); }
    inline constexpr Modint inv() const { ll x = 0, y = 0; extgcd(num, mod, x, y); return x; }
    inline constexpr ll extgcd(ll a, ll b, ll &x, ll &y) const { ll g = a; x = 1; y = 0; if(b){ g = extgcd(b, a % b, y, x); y -= a / b * x; } return g; }
    inline constexpr Modint pow(ull x) const { Modint ans = 1, cnt = *this; while(x){ if(x & 1) ans *= cnt; cnt *= cnt; x /= 2; } return ans; }
};
std::istream& operator>>(std::istream& is, Modint& x) { ll a; in(a); x = a; return is; }
inline constexpr Modint operator""_M(ull x) { return Modint(x); }
std::vector<Modint> fac(1, 1), inv(1, 1);
inline void reserve(ll a){
    if(fac.size() >= a) return;
    if(a < fac.size() * 2) a = fac.size() * 2;
    if(a >= mod) a = mod;
    while(fac.size() < a) fac.push_back(fac.back() * Modint(fac.size()));
    inv.resize(fac.size());
    inv.back() = fac.back().inv();
    for(ll i = inv.size() - 1; !inv[i - 1]; i--) inv[i - 1] = inv[i] * i;
}
inline Modint fact(ll n){ if(n < 0) return 0; reserve(n + 1); return fac[n]; }
inline Modint perm(ll n, ll r){ if(r < 0 || n < r) return 0; reserve(n + 1); return fac[n] * inv[n - r]; }
inline Modint comb(ll n, ll r){ if(r < 0 || n < r) return 0; reserve(n + 1); return fac[n] * inv[r] * inv[n - r]; }
inline Modint Mcomb(ll n, ll r){ return comb(n + r - 1, n - 1); } // r個をn部屋に分ける
inline Modint catalan(ll n){ reserve(n * 2 + 1); return fac[n * 2] * inv[n] * inv[n + 1]; }
signed main(){
    LL(n,m,d1,d2);
    n--;
    vector<int>a(m),b(m);
    rep(n+1){
        ll at=(d2-d1+1)*i+d1*n;
        if(at<m)a[at]=comb(n,i)*(i&1?-1:1);
    }
    rep(m)b[i]=comb(i+n-1,i);
    FPS A(a),B(b);
    A=A*B;
    Modint ans=0;
    rep(m)ans+=Modint(m-i)*A[i];
    out(ans);
}