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

import java.io.*;
import java.lang.*;
 public class NewYearCandle
{
public static void main(String args[]) throws IOException
{
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader stdin = new BufferedReader(isr);

boolean flag = false;
int a,b,x,y,z;
int gsum,rsum,sum;
gsum = rsum = 0;




String inputstring = null;

inputstring = stdin.readLine();
String[] split = inputstring.split(" ");
 a = Integer.parseInt(split[0]);
 b = Integer.parseInt(split[1]);

sum = a;
x = sum;y = x%b;

while(flag!=true)
{
while(x!=0)
{
x = x/b;
y = x%b;
sum = sum + x;
rsum = rsum + y;
}
gsum = gsum + sum;

if(rsum>=b)
{
z = rsum/b;
sum = rsum;
x = sum;
rsum = 0;
x = x/b;
y = x%b;
rsum = rsum + y;
sum = x;
}
else
flag = true;
}

System.out.println(gsum);

}
}