#include<bits/stdc++.h>
using namespace std; 
int n,k,ans;
int main()
{
    cin>>n>>k;
    ans=n;
    while (n)
    {
        if (n>=k)
        {
            ans+=n/k;
            n%=k;
            n+=n/k;
        }
        else
            if (n+1==k)
            {
                ans++;
                n=0;
                break;
            }
    }
    cout<<ans;
    return 0;
}