#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;
int main(){
	ll v,t,p;
	cin >> v >> t >> p;

	ll ok = 0;
	ll ng = 2e18;
	while(ng - ok > 1){
		ll mid = (ok + ng) / 2;
		if(mid - p * v - mid/t <= v)ok = mid;
		else ng = mid;
	}

	cout << ok + 1 << endl;
}