diff --git a/TaskF00/run.py b/TaskF00/run.py
new file mode 100644
index 0000000..60e4117
--- /dev/null
+++ b/TaskF00/run.py
@@ -0,0 +1,25 @@
+import re
+
+def substitute_digits(input_string):
+    def replace_digit(match):
+        digits = match.group()
+        replaced_digits = ''
+        for digit in digits:
+            if '0' <= digit <= '9':
+                replaced_digits += chr(ord('a') + int(digit))
+            else:
+                replaced_digits += digit
+        return replaced_digits
+
+    pattern = re.compile(r'\d{4}')
+    substituted_string = pattern.sub(replace_digit, input_string)
+
+    return substituted_string
+
+
+file_path = 'simple.in'
+with open(file_path, 'r', encoding = 'utf-8') as file:
+    for line in file:
+        line = line.rstrip('\n')
+        result = substitute_digits(line)
+        print(result)
diff --git a/TaskF01/run.py b/TaskF01/run.py
new file mode 100644
index 0000000..d942ccf
--- /dev/null
+++ b/TaskF01/run.py
@@ -0,0 +1,10 @@
+import re
+
+def process_file(file_path):
+    with open(file_path, 'r',encoding='utf-8') as file:
+        for line in file:
+            modified_line = re.sub(r'\b(?:[A-Z]+\w*[a-z]+\w*|[a-z]+\w*[A-Z]+\w*)\b', lambda match: match.group(0).swapcase(), line)
+            print(modified_line, end='')
+
+file_path = 'polish_wiki_excerpt.exp'
+process_file(file_path)
diff --git a/TaskF02/run.py b/TaskF02/run.py
new file mode 100644
index 0000000..32300a3
--- /dev/null
+++ b/TaskF02/run.py
@@ -0,0 +1,23 @@
+import re
+
+def analyze_line(line):
+    result = re.findall(r'([a-ząćęłńóśźż])|([A-ZĄĆĘŁŃÓŚŹŻ])|(\d)|(\s)', line, flags=re.UNICODE)
+
+    lower_case_letters = [match[0] for match in result if match[0]]
+    upper_case_letters = [match[1] for match in result if match[1]]
+    digits = [match[2] for match in result if match[2]]
+    special_characters = [match[3] for match in result if match[3]]
+
+    result = f"{len(lower_case_letters)} {len(upper_case_letters)} {len(digits)} {len(special_characters)}"
+    return result
+
+def process_file(file_path):
+    with open(file_path, 'r', encoding='utf-8') as file:
+        for line in file:
+            line = line.rstrip('\n')
+            if line:
+                result = analyze_line(line)
+                print(result)
+
+file_path = 'simple.in' 
+process_file(file_path)
diff --git a/TaskF03/run.py b/TaskF03/run.py
new file mode 100644
index 0000000..035e039
--- /dev/null
+++ b/TaskF03/run.py
@@ -0,0 +1,13 @@
+import re
+
+def process_line(line):
+    words = re.findall(r'\b(?:[a-ząćęłńóśźż]+\w*|[A-ZĄĆĘŁŃÓŚŹŻ]+\w*)\b', line, flags=re.UNICODE)
+    lowercase_words = [word for word in words if word[0].islower()]
+    uppercase_words = [word for word in words if word[0].isupper()]
+    return f"{len(lowercase_words)} {len(uppercase_words)}"
+
+file_path = 'simple.in'
+with open(file_path, 'r', encoding='utf-8') as file:
+    for line in file:
+        result = process_line(line.strip())
+        print(result)
diff --git a/TaskF04/run.py b/TaskF04/run.py
new file mode 100644
index 0000000..4d518ff
--- /dev/null
+++ b/TaskF04/run.py
@@ -0,0 +1,22 @@
+import re
+
+def delete_second_digits(input_line):
+    regex = r'\b(\d+)\b'
+    numbers = re.findall(regex, input_line)
+    
+    if len(numbers) > 1:
+        second_number = numbers[1]
+        input_line = re.sub(re.escape(second_number), '', input_line, 1)
+
+    return input_line
+
+file_path = 'simple.in'
+output_lines = []
+
+with open(file_path, 'r', encoding='utf-8') as file:
+    for line in file:
+        modified_line = delete_second_digits(line)
+        output_lines.append(modified_line)
+
+for line in output_lines:
+    print(line, end='')
diff --git a/TaskF04/simple.in b/TaskF04/simple.in
index 5d7461c..99f4584 100644
--- a/TaskF04/simple.in
+++ b/TaskF04/simple.in
@@ -1,3 +1,6 @@
 Mam 2 jabłka i 35 banananów.
 Mam 2 jabłka i 35 banananów oraz 20 gruszek.
 Widziałem 2 bociany.
+2 35 209
+12 34
+532 234 234 324
\ No newline at end of file
diff --git a/TaskF05/run.py b/TaskF05/run.py
new file mode 100644
index 0000000..7e40f91
--- /dev/null
+++ b/TaskF05/run.py
@@ -0,0 +1,15 @@
+import re
+
+def process_line(line):
+    words = re.findall(r'\w+', line)
+    if len(words) >= 3:
+        third_word = words[2]
+        replacement = 'x' * len(third_word)
+        line = re.sub(r'\b' + re.escape(third_word) + r'\b', replacement, line)
+
+    return line
+
+with open('simple.in', 'r', encoding='utf-8') as file:
+    for line in file:
+        processed_line = process_line(line)
+        print(processed_line, end='')