diff --git a/iOS/app/MMMemory.xcodeproj/project.pbxproj b/iOS/app/MMMemory.xcodeproj/project.pbxproj
index 0f7c78b..cf84228 100644
--- a/iOS/app/MMMemory.xcodeproj/project.pbxproj
+++ b/iOS/app/MMMemory.xcodeproj/project.pbxproj
@@ -10,6 +10,7 @@
 		1F083A14C69F20A6BA92A63E /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = F16A7DD61EF6CD4FB4E3DE25 /* AppDelegate.swift */; };
 		3D03666F3BC2B1F2CBB49530 /* Main.SectionSelection.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6D5F2B2E3A26F03F6825608E /* Main.SectionSelection.swift */; };
 		79FB208C9DADDA6179E588C3 /* Main.SectionGrid.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9AC22F19366076CF4168BFBD /* Main.SectionGrid.swift */; };
+		89086E3972F560A9A1A76CE4 /* Model.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9C71EDBDFFDBC96F6E8E7762 /* Model.swift */; };
 		B19B3998FA2BA651ACB1E53C /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = C1742EFC5A1E818780679340 /* Assets.xcassets */; };
 		CAFD870CA84084E45011CC23 /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 4E32B0495E4BCEA4EE0508D4 /* LaunchScreen.storyboard */; };
 		D505E64F4CD6EAEB530BF851 /* Main.Section16Buttons.swift in Sources */ = {isa = PBXBuildFile; fileRef = A38A1AA6B57483F6B44CDF78 /* Main.Section16Buttons.swift */; };
@@ -22,6 +23,7 @@
 		4E32B0495E4BCEA4EE0508D4 /* LaunchScreen.storyboard */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; path = LaunchScreen.storyboard; sourceTree = "<group>"; };
 		6D5F2B2E3A26F03F6825608E /* Main.SectionSelection.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Main.SectionSelection.swift; sourceTree = "<group>"; };
 		9AC22F19366076CF4168BFBD /* Main.SectionGrid.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Main.SectionGrid.swift; sourceTree = "<group>"; };
+		9C71EDBDFFDBC96F6E8E7762 /* Model.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Model.swift; sourceTree = "<group>"; };
 		9D774FEE86833E8A0A74387C /* App.app */ = {isa = PBXFileReference; includeInIndex = 0; lastKnownFileType = wrapper.application; path = App.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		A355A898E25602F45B88CCBA /* Main.Platform.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Main.Platform.swift; sourceTree = "<group>"; };
 		A38A1AA6B57483F6B44CDF78 /* Main.Section16Buttons.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Main.Section16Buttons.swift; sourceTree = "<group>"; };
@@ -41,6 +43,7 @@
 				9AC22F19366076CF4168BFBD /* Main.SectionGrid.swift */,
 				6D5F2B2E3A26F03F6825608E /* Main.SectionSelection.swift */,
 				0DF762100A8EDF105B6E136D /* Main.swift */,
+				9C71EDBDFFDBC96F6E8E7762 /* Model.swift */,
 			);
 			name = src;
 			path = ../src;
@@ -130,6 +133,7 @@
 				79FB208C9DADDA6179E588C3 /* Main.SectionGrid.swift in Sources */,
 				3D03666F3BC2B1F2CBB49530 /* Main.SectionSelection.swift in Sources */,
 				DB1010B8A246D47BEC6B3FA6 /* Main.swift in Sources */,
+				89086E3972F560A9A1A76CE4 /* Model.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
diff --git a/iOS/app/MMMemory.xcodeproj/project.xcworkspace/xcuserdata/mk.xcuserdatad/UserInterfaceState.xcuserstate b/iOS/app/MMMemory.xcodeproj/project.xcworkspace/xcuserdata/mk.xcuserdatad/UserInterfaceState.xcuserstate
index 1c6ecbb..f7b47a2 100644
Binary files a/iOS/app/MMMemory.xcodeproj/project.xcworkspace/xcuserdata/mk.xcuserdatad/UserInterfaceState.xcuserstate and b/iOS/app/MMMemory.xcodeproj/project.xcworkspace/xcuserdata/mk.xcuserdatad/UserInterfaceState.xcuserstate differ
diff --git a/iOS/src/Model.swift b/iOS/src/Model.swift
new file mode 100644
index 0000000..0e25dc3
--- /dev/null
+++ b/iOS/src/Model.swift
@@ -0,0 +1,28 @@
+import Foundation
+
+protocol MItemsCount {
+  var itemsCount: Int { get }
+}
+
+func memorySide() -> CGFloat {
+  return 50
+}
+
+func memorySpace() -> CGFloat {
+  return 20
+}
+
+func memoryGap() -> CGFloat {
+  return memorySide() + memorySpace()
+}
+
+func memoryItemPositions(M: MItemsCount) -> [(CGFloat, CGFloat)] {
+  var pos = [(CGFloat, CGFloat)]()
+  for i in stride(from: 0, to: M.itemsCount, by: 1) {
+    let row = floor(Double(i) / 4)
+    let x = memoryGap() + (Double(i) - row * 4) * memoryGap()
+    let y = memoryGap() + row * memoryGap()
+    pos.append((x, y))
+  }
+  return pos
+}