#include<iostream>
using namespace std;
int main(){
int n,k;
cin>>n>>k;
int ans=n,s=n;
while(s>=k){
ans+=s/k;
s=s/k+s%k;
}
cout<<ans<<endl;
return 0;
}
#include<iostream>
using namespace std;
int main(){
int n,k;
cin>>n>>k;
int ans=n,s=n;
while(s>=k){
ans+=s/k;
s=s/k+s%k;
}
cout<<ans<<endl;
return 0;
}