#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DEBUG #include "./Lib/debug.hpp" #include "./Lib/Timer.hpp" #include "./Lib/sample.hpp" #else #define dump(...) #endif /* (=^o^=) */ //#define int ll /* macro */ #define FOR(i, b, e) for(ll i = (ll)(b); i < (ll)(e); ++i) #define RFOR(i, b, e) for(ll i = (ll)(e-1); i >= (ll)(b); --i) #define REP(i, n) FOR(i, 0, n) #define RREP(i, n) RFOR(i, 0, n) #define REPC(x,c) for(const auto& x:(c)) #define REPI2(it,b,e) for(auto it = (b); it != (e); ++it) #define REPI(it,c) REPI2(it, (c).begin(), (c).end()) #define RREPI(it,c) REPI2(it, (c).rbegin(), (c).rend()) #define REPI_ERACE2(it, b, e) for(auto it = (b); it != (e);) #define REPI_ERACE(it, c) REPI_ERACE2(it, (c).begin(), (c).end()) #define ALL(x) (x).begin(),(x).end() #define cauto const auto& /* macro func */ template inline void sort(T& t) { std::sort(ALL(t)); } template inline void rsort(T& t) { std::sort((t).rbegin(), (t).rend()); } template inline void unique(T& t) { (t).erase(unique((t).begin(), (t).end()), (t).end()); } template inline bool chmax(T& t, const S& s) { if (s > t) { t = s; return true; } return false; } template inline bool chmaxE(T& t, const S& s) { if (s >= t) { t = s; return true; } return false; } template inline bool chmin(T& t, const S& s) { if (s < t) { t = s; return true; } return false; } inline void BR() { std::cout << "\n"; } /* type define */ using ll = long long; using PAIR = std::pair; using VS = std::vector; using VL = std::vector; using VVL = std::vector; using VVVL = std::vector; using VD = std::vector; template using V = std::vector; /* using std */ using std::cout; constexpr char endl = '\n'; using std::cin; using std::pair; using std::string; using std::stack; using std::queue; using std::vector; using std::list; using std::map; using std::unordered_map; using std::multimap; using std::unordered_multimap; using std::set; using std::unordered_set; using std::unordered_multiset; using std::multiset; using std::bitset; using std::priority_queue; using std::tuple; /* constant value */ constexpr ll MOD = 1000000007; //constexpr ll MOD = 998244353; /* Initial processing */ struct Preprocessing { Preprocessing() { std::cin.tie(0); std::ios::sync_with_stdio(0); }; }_Preprocessing; /* Remove the source of the bug */ inline signed pow(signed, signed) { assert(false); return -1; } /* define hash */ namespace std { template <> class hash> { public: size_t operator()(const std::pair& x) const { return hash()(1000000000 * x.first + x.second); } }; } /* input */ template std::istream& operator >> (std::istream& is, vector& vec) { for (T& x : vec) is >> x; return is; } //============================================================================================= signed main() { ll n, d, k; cin >> n >> d >> k; VVL dp(d * n + 1, VL(n + 1)); dp[0][0] = 1; FOR(i, 1, d * n + 1)FOR(j, 1, n + 1) { dp[i][j] = dp[i - 1][j] + dp[i - 1][j - 1]; if (i - d - 1 >= 0) { dp[i][j] -= dp[i - d - 1][j - 1]; } if (dp[i][j] >= MOD) { dp[i][j] %= MOD; } if (dp[i][j] < 0) { dp[i][j] += MOD; } } cout << dp[k][n] << endl; //dump(dp); }