How to separate a imported vector into colums in R?

I have a text file that only contains numbers in a single column.

I need to separate them and assign to one of 8 names I have with the range of numbers for each name.
For example I have numbers 1,2,3,4,5,6,7,8,9,10 and
I know that 1:5 is London and 6:1 is New York for example.

How do I create two columns one containing that will be London - 1... London -5, New York - 6...New York - 10. Very sorry if this is obvious I am new to R.

You can make a look-up table and join the numbers to it.

set.seed(433)     # For reproducibility
# Make a dataframe with city in one col, associated #'s in other
dt <- dat <- data.frame(city = c(rep('new york', 5), rep('london', 5)), number = 1:10)

#example data of #'s 1-10 as a vector
your_data_vector <- as.vector(sample(1:10, 10, replace = T))
                              
#change your data to a dataframe
your_data_df <- as.data.frame(your_data_vector)

#then left-join with your data
dplyr::left_join(your_data_df, dt, by = c('your_data_vector' = 'number'))

Should give you:

   your_data_vector     city
1                 6   london
2                 4 new york
3                 1 new york
4                 2 new york
5                 6   london
6                 7   london
7                 8   london
8                 1 new york
9                10   london
10                9   london

require("readr")

x3_01_2020 <- read_csv("~/x3_01_2020.txt", col_names = FALSE)

x3_01_2020$city <- c(rep("London", 5), rep("New York", 5))