C++: how do I make this program.

so I'm trying to make a program in c++ that asks the user to input an odd number(N) that is between 0 and 40(0 and 40 included) and it would display a pyramid with "*" depending on the number entered.and I would like it done with the while loop if possible thanks.
EX:
N=5
*
*
*
*
*
EX2:
N=9
*
*
*
*
*