#pragma region template #include using namespace std; using ll = long long; using ull = unsigned long long; using ld = long double; using vi = vector; using vvi = vector; using vvvi = vector; using vll = vector; using vvll = vector; using vvvll = vector; using vld = vector; using vvld = vector; using vvvld = vector; using vs = vector; using pll = pair; using vp = vector; template using pqrev = priority_queue, greater>; #define rep(i, n) for (ll i = 0, i##_end = (n); i < i##_end; i++) #define repb(i, n) for (ll i = (n)-1; i >= 0; i--) #define repr(i, a, b) for (ll i = (a), i##_end = (b); i < i##_end; i++) #define reprb(i, a, b) for (ll i = (b)-1, i##_end = (a); i >= i##_end; i--) #define ALL(a) (a).begin(), (a).end() #define SZ(x) ((ll)(x).size()) //* constexpr ll MOD = 1e9 + 7; /*/ constexpr ll MOD = 998244353; //*/ constexpr ll INF = 1e+18; constexpr ld EPS = 1e-12L; constexpr ld PI = 3.14159265358979323846L; constexpr ll GCD(ll a, ll b) { return b ? GCD(b, a % b) : a; } constexpr ll LCM(ll a, ll b) { return a / GCD(a, b) * b; } template inline bool chmax(S &a, const T &b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(S &a, const T &b) { if (b < a) { a = b; return 1; } return 0; } #ifdef OJ_LOCAL #include "dump.hpp" #else #define dump(...) ((void)0) #endif template bool print_(const T &a) { cout << a; return true; } template bool print_(const vector &vec) { for (auto &a : vec) { cout << a; if (&a != &vec.back()) { cout << " "; } } return false; } template bool print_(const vector> &vv) { for (auto &v : vv) { for (auto &a : v) { cout << a; if (&a != &v.back()) { cout << " "; } } if (&v != &vv.back()) { cout << "\n"; } } return false; } void print() { cout << "\n"; } template void print(Head &&head, Tail &&... tail) { bool f = print_(head); if (sizeof...(tail) != 0) { cout << (f ? " " : "\n"); } print(forward(tail)...); } #pragma endregion // ModInt // 参考:https://ei1333.github.io/luzhiled/snippets/math/mod-int.html // modはコンパイル時に決定 template struct ModInt { ll x; ModInt() : x(0) {} ModInt(ll y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} constexpr ModInt &operator+=(const ModInt &p) { if ((x += p.x) >= mod) x -= mod; return *this; } constexpr ModInt &operator-=(const ModInt &p) { if ((x += mod - p.x) >= mod) x -= mod; return *this; } constexpr ModInt &operator*=(const ModInt &p) { x = x * p.x % mod; return *this; } constexpr ModInt &operator/=(const ModInt &p) { *this *= p.inverse(); return *this; } constexpr ModInt operator-() { return ModInt(-x); } constexpr ModInt operator+(const ModInt &p) { return ModInt(*this) += p; } constexpr ModInt operator-(const ModInt &p) { return ModInt(*this) -= p; } constexpr ModInt operator*(const ModInt &p) { return ModInt(*this) *= p; } constexpr ModInt operator/(const ModInt &p) { return ModInt(*this) /= p; } constexpr bool operator==(const ModInt &p) { return x == p.x; } constexpr bool operator!=(const ModInt &p) { return x != p.x; } constexpr ModInt inverse() const { ll a = x, b = mod, u = 1, v = 0, t; while (b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } return ModInt(u); } constexpr ModInt pow(ll n) { ModInt ret(1), mul(x); while (n > 0) { if (n & 1) ret *= mul; mul *= mul; n >>= 1; } return ret; } friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x; } friend istream &operator>>(istream &is, ModInt &a) { ll t; is >> t; a = ModInt(t); return (is); } }; using mint = ModInt; using vm = vector; using vvm = vector; constexpr int MAX_FAC = 200010; mint fac[MAX_FAC], facinv[MAX_FAC]; void combInit() { fac[0] = mint(1); for (int i = 0; i < MAX_FAC - 1; i++) { fac[i + 1] = fac[i] * (i + 1); } facinv[MAX_FAC - 1] = fac[MAX_FAC - 1].inverse(); for (int i = MAX_FAC - 2; i >= 0; i--) { facinv[i] = facinv[i + 1] * (i + 1); } } mint comb(const ll a, const ll b) { assert(a < MAX_FAC); assert(b < MAX_FAC); if (a < 0 || b < 0 || b > a) { return mint(0); } mint ret(1); ret *= fac[a]; ret *= facinv[b]; ret *= facinv[a - b]; return ret; } mint multicomb(const ll a, const ll b) { return comb(a + b - 1, b); } mint dp[101][20010]; int main() { cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); ll n, s, k; cin >> n >> s >> k; ll m = s; rep(i, n){ m -= i*k; } if(m < 0){ print(0); return 0; } dp[0][0] = 1; repr(i, 1, n+1){ rep(j, m+1){ if(j >= i){ dp[i][j] = dp[i-1][j] + dp[i][j-i]; }else{ dp[i][j] = dp[i-1][j]; } } } print(dp[n][m]); }