#include <iostream>
#include <string> 
#include <vector> 
#include <algorithm>
#include <utility> 
#include <tuple> 
#include <cstdint> 
#include <cstdio> 
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <deque> 
#include <unordered_map> 
#include <unordered_set> 
#include <bitset> 
#include <cctype> 
#include <cmath>
using namespace std;

const int INF = 2000000000;
double X,Y,Z;

int main() {
    // Step #1. Input
    cin >> X >> Y >> Z;
    double ans=Y*Z/X;
    int re;
    if(ans-floor(ans)==0){
        re=ans-1;
    }else{
        re=ans;
    }
    cout << re << endl;

}

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

int main(){
  int a,b,Xcor,Xstep;
  cin >> a >> b >> Xcor >> Xstep;

  int Xupdown= min(2*Xcor, Xstep);

  int ans= (a <= b) ? Xupdown*(b-a) + Xcor
                    : Xupdown*(a-b-1)+ Xcor;
  
  cout << ans << endl;
}