#include <iostream>
#include <queue>
using namespace std;
int N,M,S,F;
queue <int> Q;
int main()
{
cin>>N>>M;
Q.push(N);
while(!Q.empty())
{
F = Q.front();
Q.pop();
S += F;
if(F >= M)
{
Q.push(F/M);
}
}
cout<<S;
}