Program for n-th odd number

Given a number n, print the nth odd number. The 1st odd number is 1, 2nd is 3, and so on.
Examples: 
 

Input : 3
Output : 5
First three odd numbers are 1, 3, 5, ..

Input : 5
Output : 9
First 5 odd numbers are 1, 3, 5, 7, 9, ..

 

 

The nth odd number is given by the formula 2*n-1.

 

Output: 

19

Time Complexity: O(1)

Auxiliary Space: O(1)