Nth Fibonacci Number

Given an integer n, where n represents the position in the Fibonacci sequence, compute the nth Fibonacci number. The Fibonacci sequence is defined as follows: $$F(1)=1, \ F(2)=1, \ F(n)=F(n-1)+F(n-2) \text{ for } n\geq3.$$

Your task is to read an integer n from standard input and output the nth Fibonacci number to standard output.

inputFormat

The input consists of a single integer n (where n is a positive integer and typically n is within a range that prevents integer overflow, e.g., 1 ≤ n ≤ 45).

Input is provided via standard input (stdin).

outputFormat

Output the nth Fibonacci number as a single integer. The result should be written to standard output (stdout).

1

1