#include<iostream>
using namespace std;
int main()
{
	long long int budget, number,temp1,temp2,temp3,temp4,otosidama;
	cin >> budget >> number;
	temp1 = budget % 1000;
	temp2 = budget - temp1;
	temp3 = temp2 / 1000;
	temp4 = temp3/number;
	otosidama = temp4*1000;
	cout << otosidama;
}