diff --git a/day03.sh b/day03.sh
new file mode 100755
index 0000000..885a655
--- /dev/null
+++ b/day03.sh
@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+unset PATH; readonly PATH
+source ./utils/main.sh
+
+p1() {
+  local input="$1" result=0
+
+  while [[ -n "$input" ]]; do
+    if [[ "$input" =~ mul\(([0-9]{1,3}),([0-9]{1,3})\) ]]; then
+      result="$((result + (BASH_REMATCH[1] * BASH_REMATCH[2])))"
+      input="${input#*"${BASH_REMATCH[0]}"}"
+    else
+      input=''
+    fi
+  done
+
+  printf '%d' "$result"
+}
+
+p2() {
+  local input="$1" result=0 do=true
+
+  while [[ -n "$input" ]]; do
+    if [[ "$input" =~ mul\(([0-9]{1,3}),([0-9]{1,3})\)|do\(\)|don\'t\(\) ]]; then
+      case "${BASH_REMATCH[0]}" in
+        do\(\)) do=true;;
+        don\'t\(\)) do=false;;
+        *) [[ "$do" == true ]] && result="$((result + (BASH_REMATCH[1] * BASH_REMATCH[2])))";;
+      esac
+      
+      input="${input#*"${BASH_REMATCH[0]}"}"
+    else
+      input=''
+    fi
+  done
+
+  printf '%d' "$result"
+}
+
+main "$@"