Rstudio Error Unexpected Symbol

[sbs1]

I'm new to RStudio, and I was following a video showing how to create this new data set:
data.1 <- data.frame(first.column = c(1,2,3), second.column = c(4,5,6), third column = c(7,8,9))

But when I typed this into RStudio, the error message displayed:
Error: unexpected symbol in "data.1 <- data.frame(first.column = c(1,2,3), second.column = c(4,5,6), third column"

I tried checking for typos and retyping, but keep getting the same error. Thanks to anyone who can help!

[technocrat]

@sbs1

data.1 <- data.frame(first.column = c(1,2,3), second.column = c(4,5,6), third column"

third column

needs .