https://www.acmicpc.net/problem/14924
import java.util.*;
public class Main {
public static void main(String args[]) {
Scanner sc=new Scanner(System.in);
int s=sc.nextInt();
int t=sc.nextInt();
int d=sc.nextInt();
int time=d/(s*2);
System.out.format("%d",time*t);
}
}