package test;

import java.util.Scanner;
public class aaa{
 public static void main(String args[]){
 long q,w,e,r,t;
 double a,b,c;
    Scanner input=new Scanner(System.in);
    while(input.hasNext()){
       q=input.nextLong();
       w=input.nextLong();
       e=input.nextLong();
       r=input.nextLong();
       t=input.nextLong();
       b=(r-t)*(w-e);
       c=(q-e);
       a=b/c+t;
      System.out.println(""+ new java.text.DecimalFormat("0.000000").format(a));
   }
   }
}