Problems
Find the sum
Find the sum
For the given value of $n$, compute the sum
$$
S = {1 \over 1 \cdot 2} + {1 \over 2 \cdot 3} + \cdots + {1 \over n \cdot (n + 1)}
$$
\InputFile
One positive integer $n~(n \le 1000)$.
\OutputFile
Print the sum with $6$ decimal places.
Input example #1
5
Output example #1
0.833333
Input example #2
12
Output example #2
0.923077