#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <iostream>
#include <map>
#include <queue>
#include <deque>
#include <string>
#include <stack>
#include <vector>
#include <set>
#include <tuple>
#include <utility>
#include <functional>
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
typedef tuple<int,int,int> T;
const int INF = 1000000000;
const int MOD = 1000000007;

ll v,t,p;
bool check(ll mid){
	//mid秒を達成出来るかどうか.
	if(mid / t >= mid - v * (p+1)){
		return true;
	}

	return false;
}

int main(){
	cin >> v >> t >> p;

	//まず,v*(p+1)は少なくとも達成出来る.
	//グラフをかく

	
	cout << (p+1) * v + ((p+1) * v - 1) / (t-1) + 1 << endl;
}