import java.util.*; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); double b1 = sc.nextInt(); double b2 = sc.nextInt(); double b3 = sc.nextInt(); double r = (b2 - b3) / (b1 - b2); double d = b2 - b1 * r; double ans = r * b3 + d; System.out.println(ans); } }