container from rocker/r-ver:4.0.4 exists after run command

Question

Here is my Dockerfile:

FROM rocker/r-ver:4.0.4

In cmd I build:

docker build -t myfolder/myimage .

and it builds image just fine.

Then I run

docker run myfolder/myimage

it produces:

R version 4.0.4 (2021-02-15) -- "Lost Library Book"
Copyright (C) 2021 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

>

and exits immediately. So it loads R as it is supposed to, but why does it exit?