diff --git a/p18.dyalog b/p18.dyalog
new file mode 100644
index 0000000..b51443f
--- /dev/null
+++ b/p18.dyalog
@@ -0,0 +1,7 @@
+⎕IO←0
+p←↑⊃⎕NGET'p18.txt' 1
+f←{(⍺='.')∧2<+/⍵='|':'|' ⋄ (⍺='|')∧2<+/⍵='#':'#' ⋄ (⍺='#')∧(1=+/⍵='#')∨0=+/⍵='|':'.' ⋄ ⍺}
+g←{⍵f⍤¯2{,⍵}⌺3 3⊢⍵}
+v←{×/+/'|#'∘.=,⍵} ⍝ value
+v g⍣10⊢p ⍝ part 1
+v ⍬{(≢⍺)≠n←⍺⍳⊂⍵:⍺⊃⍨n+((≢⍺)-n)|1E9-n ⋄ (⍺,⊂⍵)∇g ⍵}p ⍝ part 2
diff --git a/p18.txt b/p18.txt
new file mode 100644
index 0000000..2a072eb
--- /dev/null
+++ b/p18.txt
@@ -0,0 +1,50 @@
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