'''
Welcome to GDB Online.
GDB online is an online compiler and debugger tool for C, C++, Python, Java, PHP, Ruby, Perl,
C#, OCaml, VB, Swift, Pascal, Fortran, Haskell, Objective-C, Assembly, HTML, CSS, JS, SQLite, Prolog.
Code, Compile, Run and Debug online from anywhere in world.
'''
rad = float(input("Welcome to Area of a Circle Calculator. Please enter the Radius of the circle. "))
rad = rad*rad*3.14
print(f"The area of the circle is {rad}.")