#include <bits/stdc++.h> 
#define F first 
#define S second 
#define MAX 10000003 
using namespace std; 
#define ll long long int
#include<fstream>
#define MOD 1000000007
#define fast ios_base::sync_with_stdio(false);
#define io   cin.tie(NULL);
#define inp(arr,n) for(ll i=0;i<n;i++){cin>>arr[i];}
#define print(arr,n) for(ll i=0;i<n;i++){cout<<arr[i]<<" ";}
#define pb push_back
#define all(v) (v).begin(),(v).end()

int main()
{
	double x1,y,z;
	cin>>x1>>y>>z;
	ll ans=((y/x1)*1.0)*z;
	if(ans*x1==y*z)
		cout<<max(ans-1,0LL)<<endl;
	else
		cout<<ans<<endl;
	return 0;
}
#include<iostream>
#include<math.h>
using namespace std;
int main()
{
	float X, Y, Z;
	cin >> X >> Y >> Z;
	float a, b;
	a = Y / X;
	b = a * Z;
	if (b - floor(b) == 0)
	{
		cout << floor(b) - 1;

	}
	else
	{
		cout << floor(b);

	}
}