diff --git a/Example/Example/ViewController.swift b/Example/Example/ViewController.swift
index 9595c1d..1d6ab47 100644
--- a/Example/Example/ViewController.swift
+++ b/Example/Example/ViewController.swift
@@ -73,9 +73,9 @@ extension ViewController: UICollectionViewDataSource {
         guard let cell = collectionView.dequeueReusableCell(withReuseIdentifier: WaterfallViewCell.reuseIdentifier, for: indexPath) as? WaterfallViewCell else {
             fatalError()
         }
-        let titles: [String] = ["Shanghai", "Chongqing", "New York", "San Francisco", "Tokyo", "Phuket", "Singapore", "Wuhan", "Shenzhen", "Los Angeles"]
+        let cities: [String] = ["Shanghai", "Chongqing", "New York", "San Francisco", "Tokyo", "Phuket", "Singapore", "Wuhan", "Shenzhen", "Los Angeles"]
         let colors: [UIColor] = [.red, .magenta, .brown, .blue, .purple, .blue, .cyan, .gray, .green, .yellow, .purple]
-        cell.titleLabel.text = titles.randomElement()!
+        cell.titleLabel.text = cities.randomElement()!
         cell.titleLabel.backgroundColor = colors.randomElement()!
         return cell
     }
@@ -88,6 +88,7 @@ extension ViewController: UICollectionViewDelegateWaterfallLayout {
     }
 
     func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
-        print("did select item at \(indexPath.item)")
+        guard let selectedCell = collectionView.cellForItem(at: indexPath) as? WaterfallViewCell else { return }
+        print("Selected city is \(selectedCell.titleLabel.text ?? "None").")
     }
 }
diff --git a/README.md b/README.md
index 7283a56..cb25848 100644
--- a/README.md
+++ b/README.md
@@ -3,12 +3,12 @@ A waterfall-like (Pinterest-style) layout for UICollectionView.
 
 This library is a modified lightweight Swift version based on [`CHTCollectionViewWaterfallLayout`](https://github.com/chiahsien/CHTCollectionViewWaterfallLayout.git), very easy to integrated with your existing project just like using Apple official `UICollectionViewFlowLayout` and `UICollectionViewDelegateFlowLayout`.
 
-## Requirements
-iOS 9.0+
-
 ## Preview
 ![Preview](preview.gif)
 
+## Requirements
+iOS 9.0+
+
 ## Installation
 #### Swift Package Manager (Recommended)
 
@@ -16,7 +16,7 @@ iOS 9.0+
 - Add `https://github.com/Jinya/WaterfallLayout.git`
 - Select "Exact Version" (recommend using the latest exact version)
 
-## Package Content
+## Package content
 Only contains:
 
 - `UICollectionViewWaterfallLayout.swift`
@@ -24,7 +24,7 @@ Only contains:
 
 and a mini example project.
 
-## How to use
+## Example codes
 ```swift
 import UIKit
 import WaterfallLayout
diff --git a/Sources/WaterfallLayout/UICollectionViewWaterfallLayout.swift b/Sources/WaterfallLayout/UICollectionViewWaterfallLayout.swift
index 417d0b3..be33335 100644
--- a/Sources/WaterfallLayout/UICollectionViewWaterfallLayout.swift
+++ b/Sources/WaterfallLayout/UICollectionViewWaterfallLayout.swift
@@ -87,7 +87,7 @@ public class UICollectionViewWaterfallLayout: UICollectionViewLayout {
         let spaceColumnCount = CGFloat(columnCount - 1)
         let columnSpacing = delegate?.collectionView?(collectionView!, layout: self, minimumColumnSpacingFor: section) ?? minimumColumnSpacing
         let width = collectionViewContentWidth(ofSection: section)
-        return floor((width - (spaceColumnCount * columnSpacing)) / CGFloat(columnCount))
+        return (width - (spaceColumnCount * columnSpacing)) / CGFloat(columnCount)
     }
 
     override public func prepare() {