#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>



int main(int argc, char *argv[])
{

	unsigned long long lM = 0;
	int lN = 0;

	scanf("%llu", &lM);
	scanf("%u", &lN);

	unsigned long long lTemp = lM / 1000;

	printf("%llu", ( lTemp / lN ) *1000 );



	return 0;

}