[R] Basic misunderstanding, or problem with my installation?

[David Parkhurst]

I've just uninstalled and then reinstalled R on my windows 7 machine.
To test my understanding of data frames, I'm trying the following code.
(I plan to do other things with it, if it would only work.)
Here's the code, which seems pretty basic to me:
ls()
nums ← c(1,2,3,4,5)
ltrs ← c(“a”,”b”,”c”,”d”,”e”)
df1 ← data.frame(nums,ltrs)

Here's what happens when I try to run it:
 > ls()
character(0)
 > nums ← c(1,2,3,4,5)
Error: unexpected input in "nums \"
 > ltrs ← c(“a”,”b”,”c”,”d”,”e”)
Error: unexpected input in "ltrs \"
 > df1 ← data.frame(nums,ltrs)
Error: unexpected input in "df1 \"
 >

Am I really misunderstanding the basics, or is there something
wrong with my installation?
David