Viral Advertising

#!/bin/python3

import math
import os
import random
import re
import sys

# Complete the viralAdvertising function below.
def viralAdvertising(n):
    a=5
    list1=[5]
    list2=[]
    for i in range(0,n):
        d= (a//2)*3
        list1.append(d)
        a=d
    print(list1)
    for j in range(0,len(list1)):

        list2.append(list1[j]//2)

    list3=list2
    list3.pop()

    
    
    c=sum(list3)
    return c
    



if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    n = int(input())

    result = viralAdvertising(n)

    fptr.write(str(result) + '\n')

    fptr.close()