Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
t
h
e
f
o
u
t
h
r
o
o
t
s
o
f
-
4
Math Input
Natural Language
Math Input
