#include <iostream>

using namespace std;

int main()
{
    int n,k;
    while(cin>>n>>k)
    {
        int left=n;
        while(left/k!=0)
        {
            n=left/k+n;
            left=left%k+left/k;
        }
        cout<<n<<endl;
    }
    return 0;
}