#include<iostream>
using namespace std;

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

$azhe$