a_input_num_to_let_this_py_know_what_is_K = int(input())
just_a_value_to_save_sum_num = 0
Sn_iterator = 1
def a_def_function_to_plus_the_num_and_know_Sn_bigger_than_k_or_not(a_input_num_to_let_this_py_know_what_is_K):
    global just_a_value_to_save_sum_num
    global Sn_iterator
    just_a_value_to_save_sum_num += 1 / Sn_iterator
#    print(just_a_value_to_save_sum_num)
    Sn_iterator += 1
#    print(Sn_iterator)
    if just_a_value_to_save_sum_num > a_input_num_to_let_this_py_know_what_is_K:
        print(Sn_iterator-1)
    else:
        a_def_function_to_plus_the_num_and_know_Sn_bigger_than_k_or_not(a_input_num_to_let_this_py_know_what_is_K)
a_def_function_to_plus_the_num_and_know_Sn_bigger_than_k_or_not(a_input_num_to_let_this_py_know_what_is_K)