unit convertor

import math
import time
"""Unit Converter"""
#Welcome and variable setting
print ("Welcome to Sam's Unit Converter")
cat = input("Which category would you like to convert? we support length(l) and Weight(w):  ")
if cat == ("l"):
    unit1 = input ("Which unit would you like to convert from: ")
    unit2 = input ("Which unit would you like to convert to: ")
    num1 = input ("Enter your value: " )

    ##Calculations  

if unit1 == "cm" and unit2 == "m":
    ans = float(num1)/100       
elif unit1 == "mm" and unit2 == "cm":
    ans = float(num1)/10
elif unit1 == "m" and unit2 == "cm":
    ans = float(num1)*100
elif unit1 == "cm" and unit2 == "mm":
    ans = float(num1)*10
elif unit1 == "mm" and unit2 == "m":
    ans = float(num1)/1000
elif unit1 == "m" and unit2 == "mm":
    ans = float(num1)*1000  
elif unit1 == "km" and unit2 == "m":
    ans = float(num1)*1000
elif unit1 == "m" and unit2 == "km":
    ans = float(num1)/1000
elif unit1 == "mm" and unit2 == "km":
    ans = float(num1)/1000000
elif unit1 == "mile" and unit2 == "km";
   ans = float(num1)*0.60934