"""
Question 59
Question
Write a program to compute 1/2+2/3+3/4+...+n/n+1 with a given n input by console (n>0).

Example: If the following n is given as input to the program:

5

Then, the output of the program should be:

3.55

In case of input data being supplied to the question, it should be assumed to be a console input.

Hints
Use float() to convert an integer to a float.
Even if not converted it wont cause a problem because python by default understands the data type of a value.
"""

n = int(input())

sum = 0

for i in range(1, n+1):
    sum += i/(i+1)

# rounded to 2 decimal point
print(round(sum, 2))
