Invalid elif syntax error

Question

import string

a = input()
c = input()

if str(c) == "lb":
b = float(a) // float(0.454)
print(str(b) + " kg")

elif str(c) == "kg":
b = float(a) * float(2.204)
print (str(b) + " lb")

does any body know why this is giving me an error

Answer 1

Because the indentation is very important in Python.
Working code:

a = input()
c = input()

if str(c) == "lb":
b = float(a) // float(0.454)
print(str(b) + " kg")

elif str(c) == "kg":
b = float(a) * float(2.204)
print (str(b) + " lb")