                 while char != newLine
                 {
                     buffer.append(char)
-                    i++
+                    i += 1
                     if i >= characters.count { break }
                     char = characters[i]
                 }
                 dawg.insert(buffer)
                 buffer.removeAll()
-                i++
+                i += 1
             } while i != characters.count
             dawg.minimize(0)
             dawg.save(outputPath)

        withLetters letters: [Character],
        wordLength: Int,
        filledLetters: [Int: Character] = [Int: Character](),
        blankLetter: Character = "?") -> [String]
    {
        var filled = [Int: DawgLetter]()
        for (key, value) in filledLetters {

            wordLength: wordLength, prefix: [DawgLetter](), filled: filled,
            filledCount: filled.count, source: rootNode,
            blankLetter: String(blankLetter).utf8.first!, results: &results)
        return results.count > 0 ? results : nil
    }
}