90pts求助（样例3TLE）

#include<iostream>
using namespace std;

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