#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 const int SZ = 10010; const int MOD = 1000000000; bool used[SZ][SZ]; int comb[SZ][SZ]; int nCr(int n, int r) { if (r == 0 || n == r) return 1; 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)) % MOD; } int main() { cin.tie(nullptr); ios::sync_with_stdio(false); ll n, m; cin, n, m; n /= 1000; n %= m; cout << nCr(m, n) << endl; return 0; }