# To check the priority for the mathematical operators used in Python 
# Debug the program for better understanding

a=4.0 * (1 - (1.0/3) + (1.0/5) - (1.0/7) + (1.0/9) - (1.0/11))
print(a)

a=((25.5 * 3.5 - 3.5 * 3.5) / (40.5 - 4.5))
print(a)


# To find the perimeter of the circle
r=input('enter the radius in cm : ')
radius=float(r)
π=3.14159265359
perimeter=2*π*radius
print('the perimeter of circle is : ',perimeter)

