diff --git a/AdventOfCode2020.xcodeproj/project.pbxproj b/AdventOfCode2020.xcodeproj/project.pbxproj
index ca5b737..a1c51d3 100644
--- a/AdventOfCode2020.xcodeproj/project.pbxproj
+++ b/AdventOfCode2020.xcodeproj/project.pbxproj
@@ -1255,7 +1255,7 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 1230;
-				LastUpgradeCheck = 1230;
+				LastUpgradeCheck = 1300;
 				TargetAttributes = {
 					2617623E257DFD0800D00A66 = {
 						CreatedOnToolsVersion = 12.2;
@@ -1964,6 +1964,7 @@
 		26BD88A6258C818300E92A8E /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -1975,6 +1976,7 @@
 		26BD88A7258C818300E92A8E /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -1986,6 +1988,7 @@
 		26DD9C42258DEAC70082D4F2 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -1997,6 +2000,7 @@
 		26DD9C43258DEAC70082D4F2 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2008,6 +2012,7 @@
 		26DD9C75258F2CEE0082D4F2 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2019,6 +2024,7 @@
 		26DD9C76258F2CEE0082D4F2 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2030,6 +2036,7 @@
 		26DD9CAA2590759B0082D4F2 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2041,6 +2048,7 @@
 		26DD9CAB2590759B0082D4F2 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2052,6 +2060,7 @@
 		26DD9CF62591C4000082D4F2 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2063,6 +2072,7 @@
 		26DD9CF72591C4000082D4F2 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2074,6 +2084,7 @@
 		26DD9D2F259312410082D4F2 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2085,6 +2096,7 @@
 		26DD9D30259312410082D4F2 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2096,6 +2108,7 @@
 		26DD9DDD25949F600082D4F2 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2107,6 +2120,7 @@
 		26DD9DDE25949F600082D4F2 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2118,6 +2132,7 @@
 		26DD9E1A2595E71E0082D4F2 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
@@ -2129,6 +2144,7 @@
 		26DD9E1B2595E71E0082D4F2 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				CODE_SIGN_IDENTITY = "-";
 				CODE_SIGN_STYLE = Automatic;
 				DEVELOPMENT_TEAM = 722B335UM5;
 				ENABLE_HARDENED_RUNTIME = YES;
diff --git a/AdventOfCode2020.xcodeproj/xcshareddata/xcschemes/day20.xcscheme b/AdventOfCode2020.xcodeproj/xcshareddata/xcschemes/day20.xcscheme
new file mode 100644
index 0000000..46d33d5
--- /dev/null
+++ b/AdventOfCode2020.xcodeproj/xcshareddata/xcschemes/day20.xcscheme
@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1300"
+   version = "1.3">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "26DD9C70258F2CEE0082D4F2"
+               BuildableName = "day20"
+               BlueprintName = "day20"
+               ReferencedContainer = "container:AdventOfCode2020.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <Testables>
+      </Testables>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Release"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "26DD9C70258F2CEE0082D4F2"
+            BuildableName = "day20"
+            BlueprintName = "day20"
+            ReferencedContainer = "container:AdventOfCode2020.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "26DD9C70258F2CEE0082D4F2"
+            BuildableName = "day20"
+            BlueprintName = "day20"
+            ReferencedContainer = "container:AdventOfCode2020.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>
diff --git a/AdventOfCode2020.xcodeproj/xcshareddata/xcschemes/day23.xcscheme b/AdventOfCode2020.xcodeproj/xcshareddata/xcschemes/day23.xcscheme
new file mode 100644
index 0000000..7c92923
--- /dev/null
+++ b/AdventOfCode2020.xcodeproj/xcshareddata/xcschemes/day23.xcscheme
@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1300"
+   version = "1.3">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "26DD9D2A259312410082D4F2"
+               BuildableName = "day23"
+               BlueprintName = "day23"
+               ReferencedContainer = "container:AdventOfCode2020.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <Testables>
+      </Testables>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Release"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "26DD9D2A259312410082D4F2"
+            BuildableName = "day23"
+            BlueprintName = "day23"
+            ReferencedContainer = "container:AdventOfCode2020.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "26DD9D2A259312410082D4F2"
+            BuildableName = "day23"
+            BlueprintName = "day23"
+            ReferencedContainer = "container:AdventOfCode2020.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>