diff --git a/12.rkt b/12.rkt
index d5e05fa..60293ac 100644
--- a/12.rkt
+++ b/12.rkt
@@ -7,34 +7,32 @@
 ;; helper functions here
 
 (define d->r degrees->radians)
+(define (complex-manhat s)
+  (inexact->exact (round (+ (abs (real-part s)) (abs (imag-part s))))))
 
 (define (part1 input)
-  (define-values [dir s]
-    (for/fold ([dir 0] [s 0]) ([ins (in-list input)])
-      (match-define (cons ltr num) ins)
-      (match ltr
-        ["N" (values dir (+ s (* +i num)))]
-        ["S" (values dir (- s (* +i num)))]
-        ["E" (values dir (+ s num))]
-        ["W" (values dir (- s num))]
-        ["L" (values (+ dir (d->r num)) s)]
-        ["R" (values (- dir (d->r num)) s)]
-        ["F" (values dir (+ s (make-polar num dir)))])))
-  (inexact->exact (round (+ (abs (real-part s)) (abs (imag-part s))))))
+  (for/fold ([dir 0] [s 0] #:result (complex-manhat s)) ([ins (in-list input)])
+    (match-define (cons ltr num) ins)
+    (match ltr
+      ["N" (values dir (+ s (* +i num)))]
+      ["S" (values dir (- s (* +i num)))]
+      ["E" (values dir (+ s num))]
+      ["W" (values dir (- s num))]
+      ["L" (values (+ dir (d->r num)) s)]
+      ["R" (values (- dir (d->r num)) s)]
+      ["F" (values dir (+ s (make-polar num dir)))])))
 
 (define (part2 input)
-  (define-values [s w]
-    (for/fold ([s 0] [w 10+1i]) ([ins (in-list input)])
-      (match-define (cons ltr num) ins)
-      (match ltr
-        ["N" (values s (+ w (* +i num)))]
-        ["S" (values s (- w (* +i num)))]
-        ["E" (values s (+ w num))]
-        ["W" (values s (- w num))]
-        ["L" (values s (* w (make-polar 1 (d->r num))))]
-        ["R" (values s (* w (make-polar 1 (d->r (- num)))))]
-        ["F" (values (+ s (* w num)) w)])))
-  (inexact->exact (round (+ (abs (real-part s)) (abs (imag-part s))))))
+  (for/fold ([s 0] [w 10+1i] #:result (complex-manhat s)) ([ins (in-list input)])
+    (match-define (cons ltr num) ins)
+    (match ltr
+      ["N" (values s (+ w (* +i num)))]
+      ["S" (values s (- w (* +i num)))]
+      ["E" (values s (+ w num))]
+      ["W" (values s (- w num))]
+      ["L" (values s (* w (make-polar 1 (d->r num))))]
+      ["R" (values s (* w (make-polar 1 (d->r (- num)))))]
+      ["F" (values (+ s (* w num)) w)])))
 
 (module+ main
   (define input