MathLoops
The Fibonacci sequence starts 0, 1, 1, 2, 3, 5, 8, ... where each number is the sum of the previous two. Print the n-th number, counting from F(0) = 0.
Input
A single integer n.
Output
Print F(n).
Constraints
0 <= n <= 90
Example 1
Input
6
Output
8
0, 1, 1, 2, 3, 5, 8 so F(6) = 8.
Example 2
Input
0
Output
0
F(0) is defined as 0.