#include #include #include #include #include #include #include #include #include #include using namespace std; #define MOD 1000000000 int main(){ long long n,m; cin >> n >> m; n -= ((n/m)/1000) * 1000 * m; n /= 1000; vector> dp(m+1, vector(n+1, 0)); dp[0][0] = 1; for(int i=0; i=MOD) dp[i+1][j] -= MOD; if(j+1<=n){ dp[i+1][j+1] += dp[i][j]; if(dp[i+1][j+1]>=MOD) dp[i+1][j+1] -= MOD; } } } long long ans = dp[m][n] % MOD; cout << ans << endl; return 0; }