#include <bits/stdc++.h>
using namespace std;
bool check(double x,double y,double t,double k){
	double k1=k-x*t;
	return k/y>k1/x;
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    double x,y,t;
    cin >> x >> y >> t;
    double l=0,r=1e6,ans=0;
    while (l<=r){
		double mid=(l+r)/2;
	    if (check(x,y,t,mid)){
			ans=mid;
			l=mid+1;
		}else{
			r=mid-1;
		}
	}
	cout << int(ans);
	return 0;
}