# Nth Fibonacci Number

Easy
0/40

## Problem statement

The n-th term of Fibonacci series F(n), where F(n) is a function, is calculated using the following formula -

``````    F(n) = F(n - 1) + F(n - 2),
Where, F(1) = 1, F(2) = 1
``````

Provided 'n' you have to find out the n-th Fibonacci Number. Handle edges cases like when 'n' = 1 or 'n' = 2 by using conditionals like if else and return what's expected.

``````"Indexing is start from 1"
``````

Example :
``````Input: 6

Output: 8

Explanation: The number is ‘6’ so we have to find the “6th” Fibonacci number.
So by using the given formula of the Fibonacci series, we get the series:
[ 1, 1, 2, 3, 5, 8, 13, 21]
So the “6th” element is “8” hence we get the output.
``````
Detailed explanation ( Input/output format, Notes, Images )
##### Sample Input 1:
``````6
``````

##### Sample Output 1:
``````8
``````

##### Explanation of sample input 1 :
``````The number is ‘6’ so we have to find the “6th” Fibonacci number.
So by using the given formula of the Fibonacci series, we get the series:
[ 1, 1, 2, 3, 5, 8, 13, 21]
So the “6th” element is “8” hence we get the output.
``````

##### Expected time complexity :
``````The expected time complexity is O(n).
``````

##### Constraints:
``````1 <= 'n' <= 10000
Where ‘n’ represents the number for which we have to find its equivalent Fibonacci number.

Time Limit: 1 second
``````
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