diff --git a/2025/ruby/day_02.rb b/2025/ruby/day_02.rb
new file mode 100644
index 0000000..8437f99
--- /dev/null
+++ b/2025/ruby/day_02.rb
@@ -0,0 +1,12 @@
+ranges = DATA.read
+  .split(?,)
+  .map { it.split(?-).map(&:to_i) }
+  .map { _1.._2 }
+
+pp ranges.flat_map {|range|
+  # part one
+  # range.to_a.select { it.to_s =~ /^(.+)\1$/ }
+  range.to_a.select { it.to_s =~ /^(.+)\1+$/ }
+}.sum
+
+__END__