5 3
 1000 3
 777 17
 4 3
 2 2
 100 4
 10 4
 999 2
 6 4
 1 2
 17 3
 1 4
 26 8
 91 5
 1 3
 1000 2
 20 3
 9 4
 123 5
 1000 1000
 3 2
 3 3
 80 970
 1000 4
 1 1000

7
 1499
 825
 5
 3
 133
 13
 1997
 7
 1
 25
 1
 29
 113
 1
 1999
 29
 11
 153
 1001
 5
 4
 80
 1333
 1

#include <bits/stdc++.h>
using namespace std;
const long long INF = 1LL << 60;
const long double EPS = 1e-12;
const long double PI = acos(-1);
int a, b;
int res = 0;
bool isUpper(char c) { return c >= 'A' && c <= 'Z'; }
bool isLower(char c) { return c >= 'a' && c <= 'z'; }
bool isLetter(char c) { return c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z'; }
bool isDigit(char c) { return c >= '0' && c <= '9'; }
char toLower(char c) { return (isUpper(c)) ? (c + 32) : c; }
char toUpper(char c) { return (isLower(c)) ? (c - 32) : c; }
bool isPowOf2(int i) { return (i & i - 1) == 0; }
void input();
void solve();
void output();
int main() {
  ios::sync_with_stdio(false);
  input();
  solve();
  output();
  return 0;
}
void input() {
  cin >> a >> b;
  return;
}
void solve() {
  res += a;
  while (a > 0) {
    res += a / b;
    a /= b;
  }
  return;
}
void output() {
  cout << res << endl;
  return;
}
