#include <stdio.h>

int main()
{
	long long n, m;
	scanf("%lld", &n);
	scanf("%lld", &m);

	int o = 0;
	while (n >= m * 1000)
	{
		n -= m * 1000;
		o += 1000;
	}

	printf("%d", o);

	return 0;
}