def main():
    D = int(input())
    tax_plus = D*108
    match len(str(tax_plus)):
        case 1:
            tax_plus = "0.0" + str(tax_plus)
        case 2:
            tax_plus = "0." + str(tax_plus)
        case _:
            tax_plus = str(tax_plus)[:-2] + "." + str(tax_plus)[-2:]

    print(tax_plus)


if __name__ == "__main__":
    main()