PROBLEM STATEMENT
Alice likes lotteries.  Her favorite lottery is Pyaterochka, which is very popular in Belarus.  
Each ticket in this lottery is a rectangular grid with N rows and 5 columns, where each cell 
contains an integer between 1 and 5*N, inclusive.  All integers within a single ticket are distinct.


After the tickets are distributed, the lottery organizers randomly choose 5 distinct integers, 
each between 1 and 5*N, inclusive.  Each possible subset of 5 integers has the same probability of 
being chosen.  These integers are called the winning numbers.  A ticket is considered a winner if 
and only if it has a row which contains at least 3 winning numbers.


Alice will buy a single ticket.  Each possible ticket has the same probability of being sold.  
Return the probability that she will buy a winning ticket.

DEFINITION
Class:LotteryPyaterochka
Method:chanceToWin
Parameters:int
Returns:double
Method signature:double chanceToWin(int N)


NOTES
-Your return value must have an absolute or relative error less than 1e-9.


CONSTRAINTS
-N will be between 1 and 100, inclusive.


EXAMPLES

0)
1

Returns: 1.0

Any ticket contains just one line with some permutation of numbers 1, 2, 3, 4, 5. Ony one set of 
winning numbers is possible - {1, 2, 3, 4, 5}. So the only line of any ticket contains all 5 
winning numbers, and therefore each ticket is a winner.

1)
2

Returns: 1.0

For any set of winning numbers chosen, there's exactly one line in any ticket that contains at 
least 3 winning numbers.

2)
3

Returns: 0.5004995004995004

3)
6

Returns: 0.13161551092585574

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