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>
int main() {
  int a, b;
  int s, k;
  while (~scanf("%d%d", &a, &b)) {
    int sum = 0;
    sum += a;
    s = a;
    while (s > b) {
      k = s % b;
      s = s / b;
      sum = sum + s;
      s = s + k;
    }
    printf("%d\n", sum);
  }
  return 0;
}
