diff --git a/Lab04/code/part01/main.go b/Lab04/code/part01/main.go
index 2ca793b..2cdb577 100644
--- a/Lab04/code/part01/main.go
+++ b/Lab04/code/part01/main.go
@@ -3,31 +3,84 @@ package main
 import (
 	"fmt"
 	"github.com/dariubs/percent"
+	"io/ioutil"
+	"sort"
 	"strings"
 )
 
+type letter struct {
+	upperCase string
+	lowerCase string
+	count     int
+	frequency float64
+}
+
+type letterList []letter
+
+func (l letterList) Len() int {
+	return len(l)
+}
+
+func (l letterList) Less(i, j int) bool {
+	return l[i].frequency > l[j].frequency
+}
+
+func (l letterList) Swap(i, j int) {
+	l[i], l[j] = l[j], l[i]
+}
+
 var alphabet = []rune{
 	'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
 	'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
 }
+var letters = make([]letter, len(alphabet))
 
-func letterCount(inputText string) {
-	count := make([]int, len(alphabet))
-	frequency := make([]float64, len(alphabet))
-	totalCount := 0
-	for index, letter := range alphabet {
-		count[index] = strings.Count(inputText, string(letter))
-		count[index] += strings.Count(inputText, string(letter+32))
-		totalCount += count[index]
-	}
+func initLetterStruct() {
 	for index := range alphabet {
-		frequency[index] = percent.PercentOf(count[index], totalCount)
+		letters[index].upperCase = string(alphabet[index])
+		letters[index].lowerCase = string(alphabet[index] + 32)
 	}
-	for index, letter := range alphabet {
-		fmt.Printf("The letter %c (%c) occurs %d times in the text and the frequency in percent is %0.2f\n", letter, letter+32, count[index], frequency[index])
+}
+
+func readFile(relativePath string) string {
+	content, err := ioutil.ReadFile(relativePath)
+	if err != nil {
+		fmt.Println(err)
+	}
+	return string(content)
+}
+
+func countLetters(inputText string) int {
+	totalCount := 0
+	for index := range alphabet {
+		letters[index].count +=
+			strings.Count(inputText, letters[index].lowerCase) +
+				strings.Count(inputText, letters[index].upperCase)
+		totalCount += letters[index].count
+	}
+	return totalCount
+}
+
+func calculateFrequency(totalCount int) {
+	for index := range alphabet {
+		letters[index].frequency = percent.PercentOf(letters[index].count, totalCount)
+	}
+}
+
+func printResult() {
+	for index := range alphabet {
+		l := letters[index]
+		fmt.Printf(
+			"The letter %s (%s) occurs %d times in the text and the frequencyArray in percent is %0.2f\n",
+			l.upperCase, l.lowerCase, l.count, l.frequency,
+		)
 	}
 }
 
 func main() {
-	letterCount("This is a test to check for something.Zz")
+	initLetterStruct()
+	totalCount := countLetters(readFile("plaintext.txt"))
+	calculateFrequency(totalCount)
+	sort.Sort(letterList(letters))
+	printResult()
 }
diff --git a/Lab04/content/plaintext.txt b/Lab04/code/part01/plaintext.txt
similarity index 100%
rename from Lab04/content/plaintext.txt
rename to Lab04/code/part01/plaintext.txt