diff --git a/golf/distinct-chars-and-distinct-sizes.rkt b/golf/distinct-chars-and-distinct-sizes.rkt
new file mode 100644
index 0000000..15b1426
--- /dev/null
+++ b/golf/distinct-chars-and-distinct-sizes.rkt
@@ -0,0 +1,31 @@
+#lang racket
+; https://codegolf.stackexchange.com/questions/277441/distinct-characters-and-distinct-sizes?answertab=modifieddesc#tab-top
+
+(define solve
+(λ(s'set-count,list->set)[apply +',s{set->list,(map length [group-by(λ(x)x){sort s <}])}])
+)
+
+(define tests
+  (hash
+   "" 0
+   "a" 2
+   "aa" 3
+   "aaa" 4
+   "ab" 3
+   "aab" 5
+   "aaab" 6
+   "abab" 4
+   "abc" 4
+   "abccbcb" 7
+   "abaccac" 7
+   "abcaaccac" 8
+   "emmmmmmmm" 11
+   "abcc" 6
+   "aabcc" 6
+   "aabbcc" 5))
+
+(define ez-solve (compose solve bytes->list string->bytes/utf-8))
+
+(require rackunit)
+(for ([(in out) tests])
+  (check-equal? (ez-solve in) out in))
diff --git a/png.lisp b/png.lisp
new file mode 100644
index 0000000..eec8b31
--- /dev/null
+++ b/png.lisp
@@ -0,0 +1,26 @@
+(ql:quickload "flexi-streams")
+
+(defpackage :mehpng
+  (:use :common-lisp :flexi-streams))
+(in-package :mehpng)
+(load "utils.lisp")
+
+(defmacro hexbytes (&rest bytes)
+  (map '(vector flex:octet) (λ (x) (reread "#x" x)) bytes))
+
+(defparameter signature
+  (hexbytes 89 50 4E 47 0D 0A 1A 0A))
+
+(defgeneric bmatch (obj stream)
+  (:documentation "attempt to match OBJ with the binary input stream STREAM.
+returns (VALUES BOOLEAN T)"))
+
+(defmethod bmatch ((obj vector) stream)
+  (values
+   (block nil
+     (loop for exp across signature
+           for got = (read-byte stream nil nil)
+           do (unless (and got (= exp got))
+                (return)))
+     t)
+   nil))
diff --git a/utils.lisp b/utils.lisp
index f686448..ea8e9f9 100644
--- a/utils.lisp
+++ b/utils.lisp
@@ -1,5 +1,6 @@
 ;;; fun
 (proclaim '(inline last1 single append1 conc1))
+;; TODO: packagify and such
 
 ;; has a lot of goodies
 ;; hey whaddayaknow, pg has a with-gensyms