#include<bits/stdc++.h>
using namespace std;
int main() 
{
    long long n,k,sum,bot;
    cin>>n>>k;
    sum=n;
    bot=n;
    while(bot>=k) 
    {
        long long t=bot/k;
        sum+=t;
        bot=bot%k+t;
    }
    cout<<sum;
    return 0;
}