#define _USE_MATH_DEFINES #include <iostream> #include <iomanip> #include <algorithm> #include <cmath> #include <string> #include <list> #include <queue> #include <vector> #include <complex> #include <set> ///////// #define REP(i, x, n) for(int i = x; i < n; i++) #define rep(i,n) REP(i,0,n) #define P(p) cout<<(p)<<endl; ///////// typedef long long LL; typedef long double LD; ///////// using namespace::std; ///////// const LL mod = (LL)1e9; const int maxC = 10000; LL c[maxC][maxC/2]; LL ccc(LL n,LL k){ LL ans; LL kk = min(k,n-k); if(n<maxC && kk < maxC && c[n][kk] != 0){ ans = c[n][kk]; } else if(kk ==0 ){ if(n<maxC){ c[n][kk] = 1; } ans = 1; }else if( kk==1){ if(n<maxC){ c[n][kk] = n%mod; } ans = n%mod; } else{ ans = (ccc(n-1,kk-1)%mod+ccc(n-1,kk)%mod)%mod; if(n<maxC && kk < maxC){ c[n][kk] = ans; } } return ans; } int main(void){ std::cin.tie(0); std::ios::sync_with_stdio(false); std::cout << std::fixed;// //cout << setprecision(6);// LL N,M; cin>>N>>M; LL ama = (N%(M*1000))/1000; //rep(i,maxC)rep(j,maxC)c[i][j]=-1; //N C ama P(ccc(M,ama)); return 0; }