#include <stdio.h>

long solve(long n, long m){
  long per_k;
  per_k = n / m / 1000;
  return per_k * 1000;
}

int main(void){
  long n, m, res;

  scanf("%ld", &n);
  scanf("%ld", &m);

  res = solve(n, m);
  printf("%ld", res);

  return 0;
}