The Fibonacci numbers
are defined as follows:
Therefore, the first Fibonacci
numbers are 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, …
For every given natural number
,
compute
.
Input
Input consists of several
.
Assume
.
Output
For every given
,
print
.
About statements
The official statement of a problem is always the one
in the PDF document. The HTML version of the statement
is also given to help you, but may contain some content
that is not well displayed. In case of doubt, always use the PDF.