diff --git a/Memorize.xcodeproj/project.pbxproj b/Memorize.xcodeproj/project.pbxproj
index ee6f11c..8a8fb19 100644
--- a/Memorize.xcodeproj/project.pbxproj
+++ b/Memorize.xcodeproj/project.pbxproj
@@ -11,6 +11,8 @@
 		240EDC412998A3B900A46AC9 /* ContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 240EDC402998A3B900A46AC9 /* ContentView.swift */; };
 		240EDC432998A3BA00A46AC9 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 240EDC422998A3BA00A46AC9 /* Assets.xcassets */; };
 		240EDC462998A3BA00A46AC9 /* Preview Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 240EDC452998A3BA00A46AC9 /* Preview Assets.xcassets */; };
+		245099F32998EAD6000CE9DA /* MemoryGame.swift in Sources */ = {isa = PBXBuildFile; fileRef = 245099F22998EAD6000CE9DA /* MemoryGame.swift */; };
+		245099F52998EC71000CE9DA /* EmojiMemoryGame.swift in Sources */ = {isa = PBXBuildFile; fileRef = 245099F42998EC71000CE9DA /* EmojiMemoryGame.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
@@ -19,6 +21,8 @@
 		240EDC402998A3B900A46AC9 /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
 		240EDC422998A3BA00A46AC9 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		240EDC452998A3BA00A46AC9 /* Preview Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = "Preview Assets.xcassets"; sourceTree = "<group>"; };
+		245099F22998EAD6000CE9DA /* MemoryGame.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MemoryGame.swift; sourceTree = "<group>"; };
+		245099F42998EC71000CE9DA /* EmojiMemoryGame.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EmojiMemoryGame.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -53,6 +57,8 @@
 			children = (
 				240EDC3E2998A3B900A46AC9 /* MemorizeApp.swift */,
 				240EDC402998A3B900A46AC9 /* ContentView.swift */,
+				245099F22998EAD6000CE9DA /* MemoryGame.swift */,
+				245099F42998EC71000CE9DA /* EmojiMemoryGame.swift */,
 				240EDC422998A3BA00A46AC9 /* Assets.xcassets */,
 				240EDC442998A3BA00A46AC9 /* Preview Content */,
 			);
@@ -137,8 +143,10 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				245099F32998EAD6000CE9DA /* MemoryGame.swift in Sources */,
 				240EDC412998A3B900A46AC9 /* ContentView.swift in Sources */,
 				240EDC3F2998A3B900A46AC9 /* MemorizeApp.swift in Sources */,
+				245099F52998EC71000CE9DA /* EmojiMemoryGame.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
diff --git a/Memorize/ContentView.swift b/Memorize/ContentView.swift
index 1313308..1203249 100644
--- a/Memorize/ContentView.swift
+++ b/Memorize/ContentView.swift
@@ -14,42 +14,17 @@ struct ContentView: View {
         VStack {
             ScrollView {
                 LazyVGrid(columns: [GridItem(.adaptive(minimum: 65))]) {
-                    ForEach(emojis[0..<emojiCount], id: \.self) {
-                        emoji in CardView(content: emoji).aspectRatio(2/3, contentMode: .fit)
+                    ForEach(emojis[0 ..< emojiCount], id: \.self) {
+                        emoji in CardView(content: emoji).aspectRatio(2 / 3, contentMode: .fit)
                     }
                 }
             }
-            .foregroundColor(/*@START_MENU_TOKEN@*/.red/*@END_MENU_TOKEN@*/)
-            Spacer()
-            HStack{
-                remove
-                Spacer()
-                add
-            }
+            .foregroundColor(/*@START_MENU_TOKEN@*/ .red/*@END_MENU_TOKEN@*/)
             .padding(.horizontal)
             .font(.largeTitle)
         }
         .padding(.horizontal)
     }
-    
-    var remove: some View {
-        Button(action: {
-            if emojiCount > 1{
-                emojiCount -= 1
-            }
-        }, label: {
-            Image(systemName: "minus.circle")
-        })
-    }
-    var add: some View {
-        Button(action: {
-            if emojiCount < emojis.count {
-                emojiCount += 1
-            }
-        }, label: {
-            Image(systemName: "plus.circle")
-        })
-    }
 }
 
 struct CardView: View {
@@ -78,17 +53,6 @@ struct CardView: View {
     }
 }
 
-
-
-
-
-
-
-
-
-
-
-
 struct ContentView_Previews: PreviewProvider {
     static var previews: some View {
         ContentView()
diff --git a/Memorize/EmojiMemoryGame.swift b/Memorize/EmojiMemoryGame.swift
new file mode 100644
index 0000000..3132c2a
--- /dev/null
+++ b/Memorize/EmojiMemoryGame.swift
@@ -0,0 +1,23 @@
+//
+//  EmojiMemoryGame.swift
+//  Memorize
+//
+//  Created by ching on 2023/2/12.
+//
+
+import SwiftUI
+
+// viewmodel
+class EmojiMemoryGame {
+    static let emojis = ["🚌", "🚙", "🚗", "🚕", "🏎", "🚎", "🚓"]
+
+    static func createMemoryGame() -> MemoryGame<String> {
+        MemoryGame<String>(numberOfPairsOfCards: 5) { pairIndex in EmojiMemoryGame.emojis[pairIndex] }
+    }
+
+    private var model: MemoryGame<String> = createMemoryGame()
+
+    var cards: [MemoryGame<String>.Card] {
+        return model.cards
+    }
+}
diff --git a/Memorize/MemoryGame.swift b/Memorize/MemoryGame.swift
new file mode 100644
index 0000000..ec65cdf
--- /dev/null
+++ b/Memorize/MemoryGame.swift
@@ -0,0 +1,31 @@
+//
+//  MemoryGame.swift
+//  Memorize
+//
+//  Created by ching on 2023/2/12.
+//
+
+import Foundation
+
+// model
+struct MemoryGame<CardContent> {
+    private(set) var cards: [Card]
+
+    func choose(_ card: Card) {}
+
+    init(numberOfPairsOfCards: Int, createCardContent: (Int) -> CardContent) {
+        cards = [Card]()
+        //
+        for pairIndex in 0 ..< numberOfPairsOfCards {
+            let content: CardContent = createCardContent(pairIndex)
+            cards.append(Card(content: content))
+            cards.append(Card(content: content))
+        }
+    }
+
+    struct Card {
+        var isFaceUp: Bool = false
+        var isMatched: Bool = false
+        var content: CardContent
+    }
+}