print("1<=a,b,c<=100\n\n")
print("a,b and c are integer\n\n")
a=int(input("Enter 1st pole heights::- "))
b=int(input("Enter 2nd pole heights:- "))
c=int(input("Enter 3rd pole heights:- "))
if(b-a==c-b):
        print("This arrangement of pole is beautiful")
else:
        print("This arrangement of poles is not beautiful")
