#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <algorithm>
#include <functional>
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <cctype>
#include <string>

using namespace std;

typedef long long ll;

int main() {
  ll n, m;
  cin >> n;
  cin >> m;
  std::cout << (n/m)-((n/m)%1000) << std::endl;
}