re = /^[^-]*-[^-]*\K.*$/im
str = '60166213
60173866-4533
60167323-9439-1259801
NL170-2683-1262201
60174710-1-A12-4'
subst = ''
result = str.gsub(re, subst)
# Print the result of the substitution
puts result
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html