#include using i32 = int_fast32_t; using i64 = int_fast64_t; using u32 = uint_fast32_t; using u64 = uint_fast64_t; using f64 = double; using f80 = long double; #define FOR(v, a, b) for(i64 v = (a); v < (b); ++v) #define FORE(v, a, b) for(i64 v = (a); v <= (b); ++v) #define REP(v, n) FOR(v, 0, n) #define REPE(v, n) FORE(v, 0, n) #define REV(v, a, b) for(i64 v = (a); v >= (b); --v) #define ALL(x) (x).begin(), (x).end() #define RALL(x) (x).rbegin(), (x).rend() #define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it) #define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it) #define EXIST(c,x) ((c).find(x) != (c).end()) #define fst first #define snd second #define UNIQ(v) (v).erase(unique(ALL(v)), (v).end()) #define bit(i) (1LL<<(i)) #ifdef DEBUG #include #else #define dump(...) ((void)0) #endif using namespace std; template void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost< istream& operator>>(istream &is, vector &v){for(auto &a : v) is >> a; return is;} template void puts_all(const T &value){std::cout << value << "\n";} template void puts_all(const T &value, const Args&... args){std::cout << value << " ";puts_all(args...);} template bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);} template bool chmax(T &a, const U &b){return (a void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);} template auto make_vector(int n, int m, const T &value){return vector>(n, vector(m, value));} struct Init{ Init(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(12); cerr << fixed << setprecision(12); } }init; template class ModInt{ public: uint64_t val; constexpr ModInt(): val(0){} constexpr ModInt(std::int64_t n){ if(n >= M) val = n % M; else if(n < 0) val = n % M + M; else val = n; } inline constexpr auto operator+(const ModInt &a) const {return ModInt(val + a.val);} inline constexpr auto operator-(const ModInt &a) const {return ModInt(val - a.val);} inline constexpr auto operator*(const ModInt &a) const {return ModInt(val * a.val);} inline constexpr auto operator/(const ModInt &a) const {return ModInt(val * a.inv().val);} inline constexpr auto& operator=(const ModInt &a){val = a.val; return *this;} inline constexpr auto& operator+=(const ModInt &a){if((val += a.val) >= M) val -= M; return *this;} inline constexpr auto& operator-=(const ModInt &a){if(val < a.val) val += M; val -= a.val; return *this;} inline constexpr auto& operator*=(const ModInt &a){(val *= a.val) %= M; return *this;} inline constexpr auto& operator/=(const ModInt &a){(val *= a.inv().val) %= M; return *this;} inline constexpr bool operator==(const ModInt &a) const {return val == a.val;} inline constexpr bool operator!=(const ModInt &a) const {return val != a.val;} inline constexpr auto& operator++(){*this += 1; return *this;} inline constexpr auto& operator--(){*this -= 1; return *this;} inline constexpr auto operator++(int){auto t = *this; *this += 1; return t;} inline constexpr auto operator--(int){auto t = *this; *this -= 1; return t;} inline constexpr static ModInt power(int64_t n, int64_t p){ if(p < 0) return power(n, -p).inv(); int64_t ret = 1, e = n; for(; p; (e *= e) %= M, p >>= 1) if(p & 1) (ret *= e) %= M; return ret; } inline constexpr static ModInt inv(int64_t a){ int64_t b = M, u = 1, v = 0; while(b){ int64_t t = a / b; a -= t * b; std::swap(a,b); u -= t * v; std::swap(u,v); } u %= M; if(u < 0) u += M; return u; } inline constexpr static auto frac(int64_t a, int64_t b){return ModInt(a) / ModInt(b);} inline constexpr auto power(int64_t p) const {return power(val, p);} inline constexpr auto inv() const {return inv(val);} friend inline constexpr auto operator-(const ModInt &a){return ModInt(-a.val);} friend inline constexpr auto operator+(int64_t a, const ModInt &b){return ModInt(a) + b;} friend inline constexpr auto operator-(int64_t a, const ModInt &b){return ModInt(a) - b;} friend inline constexpr auto operator*(int64_t a, const ModInt &b){return ModInt(a) * b;} friend inline constexpr auto operator/(int64_t a, const ModInt &b){return ModInt(a) / b;} friend std::istream& operator>>(std::istream &s, ModInt &a){s >> a.val; return s;} friend std::ostream& operator<<(std::ostream &s, const ModInt &a){s << a.val; return s;} template inline static auto div(){ static auto value = inv(N); return value; } }; using mint = ModInt<1000000007>; template , typename Minus = std::minus> class CumulativeSum1D{ std::vector data; const int N; const Add add; const Minus minus; bool is_built = false; public: CumulativeSum1D(const std::vector &a, const T &e = 0, const Add &add = Add(), const Minus &minus = Minus()): N(a.size()), add(add), minus(minus) { data.assign(N+1, e); for(int i = 0; i < N; ++i) data[i+1] = a[i]; } CumulativeSum1D(int N, const T &e = 0, const Add &add = Add(), const Minus &minus = Minus()): N(N), add(add), minus(minus) { data.assign(N+1, e); } inline void update(int i, const T &val){ assert(not is_built); data[i+1] = add(data[i+1], val); } inline void build(){ assert(not is_built); for(int i = 0; i < N; ++i) data[i+1] = add(data[i+1], data[i]); is_built = true; } /** * @attention [i, j) */ inline T get(int i, int j) const { assert(is_built); return minus(data[j], data[i]); } }; int main(){ int N, d, K; while(cin >> N >> d >> K){ int M = N * d + 1; vector dp(M); dp[0] = 1; REP(i,N){ auto s = CumulativeSum1D(dp); s.build(); REP(j,M){ dp[j] = s.get(max(j-d, i), j); } } puts_all(dp[K]); } return 0; }