CAFE C++

#include <bits/stdc++.h>
using namespace std;

int n, k, res = 0;

void read()
{
    cin>>n>>k;
}


bool check(int v)
{
    long long s = 0;
    long long mau = 1;
    while (v/mau!= 0)
    {
        s=s+v/mau;
        mau=mau*k;
    }
    if (s >= n) return true;
    else return false;
}

/*void bs(int l, int r){
    if (l > r) return;
    int mid = (l + r)/2;
    if (check(mid) == true)
    {
        res = mid;
        bs(l, mid-1);
    }
    else bs(mid+1,r);
}*/

void bs(int l, int r)
{
    int mid;
    while(l<=r)
    {
        mid = (l + r)/2;
        if (check(mid) == true)
        {
            res = mid;
            r=mid-1;
        }
            else l=mid+1;
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
    freopen( "CAFE.inp", "r", stdin);
    freopen( "CAFE.out", "w", stdout);
    read();
    bs(1,n);
    cout<<res;
}