#include<bits/stdc++.h>
using namespace std;
int main(){
    int a,b,c,m=0;
    cin>>a>>b>>c;
    m=a*c;
    double x=m,s=m;
    x/=(b-a);
    x*=a;
    floor(x);
    s+=x;
    cout<<int(s)<<endl;
    return 0;
}

/**************************************************************
	Problem: 1548
	User: admin
	Language: C++
	Result: Accepted
	Time:48 ms
	Memory:2072 kb
****************************************************************/