#include<bits/stdc++.h>
using namespace std;
const int N=1e4+5,INF=0x3f3f3f3f;
int heizi(int x,int y){
	return x/y+(x%y!=0);
}
int n,q;
int main()
{
	cin>>n>>q;
	int d=1,end=(q-1)*n;
	while(d<=end)d=heizi(q*d,q-1);
	cout<<q*n+1-d;
	return 0;
}

一定AC