import java.util.Arrays; import java.util.HashSet; import java.util.LinkedList; import java.util.Scanner; import java.util.Set; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); final long D = sc.nextLong(); final long D8 = D * 8; final long upper_ans = D + (D8 / 100); final long lower_ans = D8 % 100; System.out.println(upper_ans + "." + lower_ans); } }