S Sequence II
Adapted by Neilor Tonin, URI 
Brazil
Adapted by Neilor Tonin, URI Brazil
Write an algorithm to calculate and write the value of S, S being given by:
S = 1 + 3/2 + 5/4 + 7/8 + ... + 39/?
There is no input in this problem.
The output contains a value corresponding to the value of S.
The value should be printed with two digits after the decimal point.
| Input Sample | Output Sample |