In mathematical terms, the sequence Fn of Fibonacci numbers is defined by the recurrence relation: Fn = Fn-1 + Fn-2 with seed values and F0 = 0 and F1 = 1 .
Create a smart contract as follows which calculates the value of Fn in the fibonacci sequence:

function fibonacci(uint n) public returns (uint): This function should take 1 parameter of type uint256, n, as input and output the value of Fn in the fibonacci sequence as described above.

Examples

Example

Function

Parameter

Returns

1

fibonacci()

0

0

2

fibonacci()

1

1

3

fibonacci()

6

8