diff --git a/src/y2025/d12/solve.rb b/src/y2025/d12/solve.rb
new file mode 100755
index 0000000..817be9e
--- /dev/null
+++ b/src/y2025/d12/solve.rb
@@ -0,0 +1,39 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require 'bundler/setup'
+require 'aoc/point'
+
+sections = ARGF.read.split("\n\n")
+
+presents = sections[...-1].map { |p|
+  shape = []
+  p.lines[1..].each_with_index { |l, row|
+    l.strip.chars.each_with_index { |c, col|
+      shape.push AoC::Point2[col, row] if c == ?#
+    }
+  }
+  shape
+}
+
+class Tree
+  attr_reader :width, :height, :requirements
+
+  def initialize(width, height, requirements)
+    @width = width
+    @height = height
+    @requirements = requirements
+  end
+
+  def to_s
+    "#{width}x#{height} [#{requirements.join(', ')}]"
+  end
+end
+
+trees = sections[-1].scan(/(\d+)x(\d+):(( \d+)+)/).map { |w, h, r|
+  Tree.new w.to_i, h.to_i, r.split.map(&:to_i)
+}
+
+presents.each { |p| puts p.map(&:to_s).join(' ') }
+
+puts trees.count { |t| t.width * t.height >= t.requirements.sum { |r| r * 9 } }