#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
using namespace std;

#define MOD 1000000000

int main(){
	long long n,m;
	cin >> n >> m;
	n -= ((n/m)/1000) * 1000 * m;

	n /= 1000;

	cerr << n << " " << m << endl;

	vector<vector<long long>> dp(2, vector<long long>(n+1, 0));
	dp[0][0] = 1;
	for(int i=0; i<m; ++i){
		int pos = i%2;
		int next = (i+1)%2;

		fill(dp[next].begin(), dp[next].end(), 0);
		
		for(int j=max(0LL, n-(m-i)); j<=i+1 && j<=n; ++j){
			
			dp[next][j] += dp[pos][j];
			if(dp[next][j]>=MOD) dp[next][j] -= MOD;

			if(j+1<=n){
				dp[next][j+1] += dp[pos][j];
				if(dp[next][j+1]>=MOD) dp[next][j+1] -= MOD;
			}
		}
		
	}

	long long ans = dp[m%2][n] % MOD;
	cout << ans << endl;
	return 0;
}