#include #include #include #include #include #include #include #define REP(i, a, b) for (int i = int(a); i < int(b); i++) using namespace std; using ll = long long int; using P = pair; // clang-format off #ifdef _DEBUG_ #define dump(...) do{ cerr << __LINE__ << ":\t" << #__VA_ARGS__ << " = "; PPPPP(__VA_ARGS__); cerr << endl; } while(false) template void PPPPP(T t) { cerr << t; } template void PPPPP(T t, S... s) { cerr << t << ", "; PPPPP(s...); } #else #define dump(...) do{ } while(false) #endif template vector make_v(size_t a, T b) { return vector(a, b); } template auto make_v(size_t a, Ts... ts) { return vector(a, make_v(ts...)); } template bool chmin(T &a, T b) { if (a > b) {a = b; return true; } return false; } template bool chmax(T &a, T b) { if (a < b) {a = b; return true; } return false; } template void print(T a) { cout << a << endl; } template void print(T a, Ts... ts) { cout << a << ' '; print(ts...); } template istream &operator,(istream &in, T &t) { return in >> t; } // clang-format on template class ModInt { ll n; ModInt constexpr inverse() const { return ModInt::pow(*this, MOD - 2); } public: ModInt() : n(0) {} ModInt(ll _n) : n(((_n % MOD) + MOD) % MOD) {} ModInt operator+=(const ModInt &m) { n += m.n; if (n >= MOD) n -= MOD; return *this; } ModInt operator-=(const ModInt &m) { n -= m.n; if (n < 0) n += MOD; return *this; } ModInt operator*=(const ModInt &m) { n *= m.n; if (n >= MOD) n %= MOD; return *this; } ModInt operator/=(const ModInt &m) { (*this) *= m.inverse(); return *this; } friend ModInt operator+(ModInt t, const ModInt &m) { return t += m; } friend ModInt operator-(ModInt t, const ModInt &m) { return t -= m; } friend ModInt operator*(ModInt t, const ModInt &m) { return t *= m; } friend ModInt operator/(ModInt t, const ModInt &m) { return t /= m; } ModInt operator=(const ll l) { n = l % MOD; if (n < 0) n += MOD; return *this; } friend ostream &operator<<(ostream &out, const ModInt &m) { out << m.n; return out; } friend istream &operator>>(istream &in, ModInt &m) { ll l; in >> l; m = l; return in; } static constexpr ModInt pow(const ModInt x, ll p) { ModInt ans = 1; for (ModInt m = x; p > 0; p /= 2, m *= m) { if (p % 2) ans *= m; } return ans; } }; using mint = ModInt<1000000000>; mint operator"" _m(unsigned long long m) { return mint(m); } #include int main() { cin.tie(nullptr); ios::sync_with_stdio(false); ll n, m; cin, n, m; n /= 1000; n %= m; auto used = make_v(m + 1, n + 1, false); auto comb = make_v(m + 1, n + 1, 0_m); function nCr = [&](int n, int r) { if (r == 0 || n == r) return 1_m; if (used[n][r]) return comb[n][r]; used[n][r] = true; return comb[n][r] = nCr(n - 1, r - 1) + nCr(n - 1, r); }; cout << nCr(m, n) << endl; return 0; }