Deployment to Hiroku failed

[ShihTzuRescuer]

How do we overcome the problem below if we are novices? Thanks.

-----> Ruby app detected -----> Installing bundler 1.17.3 -----> Removing BUNDLED WITH version in the Gemfile.lock -----> Compiling Ruby/Rails Command: 'set -o pipefail; curl -L --fail --retry 5 --retry-delay 1 --connect-timeout 3 --max-time 30 https://s3-external-1.amazonaws.com/heroku-buildpack-ruby/heroku-18/ruby-2.2.4.tgz -s -o - | tar zxf - ' failed on attempt 1 of 3. Command: 'set -o pipefail; curl -L --fail --retry 5 --retry-delay 1 --connect-timeout 3 --max-time 30 https://s3-external-1.amazonaws.com/heroku-buildpack-ruby/heroku-18/ruby-2.2.4.tgz -s -o - | tar zxf - ' failed on attempt 2 of 3. ! ! The Ruby version you are trying to install does not exist on this stack. !
! You are trying to install ruby-2.2.4 on heroku-18. !
! Ruby ruby-2.2.4 is present on the following stacks: !
! - cedar-14 ! - heroku-16 !
! Heroku recommends you use the latest supported Ruby version listed here: ! https://devcenter.heroku.com/articles/ruby-support#supported-runtimes !
! For more information on syntax for declaring a Ruby version see: ! https://devcenter.heroku.com/articles/ruby-versions ! ! Push rejected, failed to compile Ruby app. ! Push failed

[mobentec]

I'm experiencing the same issue.