#include <bits/stdc++.h>
using namespace std;

int main()
{
int i;
int P;
int N;
int K;
int iCnt;

	cin >> N;
	cin >> K;
	if( N <= K )
		cout << 501 << endl;
	else if( ( N - 1 ) % ( K + 1 ) == 0 )
		cout << 499 << endl;
	else
		cout << 501 << endl;

	return 0;
}