"""

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

"""
num = int(input())
sum = 0.0
for i in range(1,num+1):
    sum += float(i/(i+1))

print("%.2f" % sum)
2d0a5a2cebc163bdb4244ad7a60a68418e2632d7
<mask token>

<mask token>
for i in range(1, num + 1):
    sum += float(i / (i + 1))
print('%.2f' % sum)

<mask token>
num = int(input())
sum = 0.0
for i in range(1, num + 1):
    sum += float(i / (i + 1))
print('%.2f' % sum)

"""

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

"""
num = int(input())
sum = 0.0
for i in range(1,num+1):
    sum += float(i/(i+1))

print("%.2f" % sum)