diff --git a/12.23.txt b/12.23.txt
new file mode 100644
index 0000000..9a4aa07
--- /dev/null
+++ b/12.23.txt
@@ -0,0 +1,5 @@
+Reeves K. 0661234567
+Cage N. 0953451234
+Depp J. 0507654321
+DiCaprio L. 0664561234
+Freeman M. 0509876123
\ No newline at end of file
diff --git a/12.24.txt b/12.24.txt
new file mode 100644
index 0000000..2ec42c7
--- /dev/null
+++ b/12.24.txt
@@ -0,0 +1,10 @@
+3 red iron
+5 green iron 
+5 blue wood
+7 red cardboard
+6 blue iron
+2 green cardboard
+4 red wood
+8 yellow wood
+2 blue cardboard
+6 yellow iron
\ No newline at end of file
diff --git a/12.47.py b/12.47.py
new file mode 100644
index 0000000..fc879fb
--- /dev/null
+++ b/12.47.py
@@ -0,0 +1,40 @@
+def check_indent(filename):
+    with open(filename) as f:
+        used = [(0, '')]
+        lines = f.readlines()
+
+        for line in lines:
+            stripped_line = line.lstrip()
+            indent = len(line) - len(stripped_line)
+
+            if indent > used[-1][0] and used[-1][1] == '':
+                print(line)
+                return False
+            if indent <= used[-1][0] and used[-1][1] == ':':
+                print(line)
+                return False
+            if indent < used[-1][0]:
+                while indent < used[-1][0]:
+                    used.pop()
+                if indent != used[-1][0]:
+                    print(line)
+                    return False
+                if ':' == line.rstrip()[-1]:
+                    used.append((indent, ':'))
+                else:
+                    used.append((indent, ''))
+            elif ':' == line.rstrip()[-1]:
+                used.append((indent, ':'))
+            else:
+                used.append((indent, ''))
+            print(lines.index(line)+1, indent, used)
+                                           
+    return True 
+
+if __name__ == '__main__':
+    filename = 'exercises/12.47.txt'
+    print(check_indent(filename))
+
+
+        
+
diff --git a/12.47.txt b/12.47.txt
new file mode 100644
index 0000000..b0dfa49
--- /dev/null
+++ b/12.47.txt
@@ -0,0 +1,32 @@
+def check_indent(filename):
+    with open(filename) as f:
+        used = [(0, '')]
+        lines = f.readlines()
+        for line in lines:
+            stripped_line = line.lstrip()
+            indent = len(line) - len(stripped_line)
+            if indent > used[-1][0] and used[-1][1] == '':
+                print(line)
+                return False
+            if indent <= used[-1][0] and used[-1][1] == ':':
+                print(line)
+                return False
+            if indent < used[-1][0]:
+                while indent < used[-1][0]:
+                    used.pop()
+                if indent != used[-1][0]:
+                    print(line)
+                    return False
+                if ':' == line.rstrip()[-1]:
+                    used.append((indent, ':'))
+                else:
+                    used.append((indent, ''))
+            elif ':' == line.rstrip()[-1]:
+                used.append((indent, ':'))
+            else:
+                used.append((indent, ''))
+            print(lines.index(line)+1, indent, used)            
+    return True 
+if __name__ == '__main__':
+    filename = 'exercises/12.47.txt'
+    print(check_indent(filename))
\ No newline at end of file
diff --git a/classwork4.py b/classwork4.py
new file mode 100644
index 0000000..f4453e9
--- /dev/null
+++ b/classwork4.py
@@ -0,0 +1,63 @@
+# Завдання 12.23
+from collections import defaultdict
+
+def phone_number(filename, name):
+    f = open(filename)
+    names = f.readlines()
+    name = name.split()
+    name = f'{name[0].title()} {name[1].title()}.'
+    for row in names:
+        if f'{row.split()[0]} {row.split()[1]}' == name:
+            return name, row.split()[2]
+    f.close()
+
+    return 'співробітника не знайдено'
+
+filename = 'exercises/12.23.txt'  
+name = input("Введіть ім'я: ")     
+print(f'Телефон співробітника {phone_number(filename, name)[0]}: {phone_number(filename, name)[1]}')
+
+# Завдання 12.24
+
+def cubes_by_colours(filename):
+    f = open(filename)
+    rows = f.readlines()
+    colours_dict = defaultdict(int)
+    areas_dict = defaultdict(int)
+    cubes_dict = defaultdict(tuple)
+
+    for cube in rows:
+        colours_dict[cube.split()[1]] += 1
+    for cube in rows:
+        areas_dict[cube.split()[1]] += int(cube.split()[0])**3
+    for colour in areas_dict.keys():
+        cubes_dict[colour] = (f'Кількість кубиків: {colours_dict[colour]}',
+            f"Сумарний об'єм: {areas_dict[colour]}")
+    f.close()
+
+    return cubes_dict
+
+def cubes_by_materials(filename):
+    f = open(filename)
+    rows = f.readlines()
+    wood_cubes = 0
+    iron_cubes = 0
+
+    for cube in rows:
+        if cube.split()[2] == 'wood' and int(cube.split()[0]) == 3:
+            wood_cubes += 1
+        if cube.split()[2] == 'iron' and int(cube.split()[0]) > 5:
+            iron_cubes += 1
+
+    return wood_cubes, iron_cubes
+
+
+filename = 'exercises/12.24.txt'
+for cube_colour, info in cubes_by_colours(filename).items():
+    print(f"{cube_colour}: {info}")
+
+cubes = cubes_by_materials(filename)
+print(f"\nКількість дерев'яних кубиків із ребром 3: {cubes[0]}")
+print(f"Кількість металевих кубиків із ребром більшим за 5: {cubes[1]}")
+
+        
\ No newline at end of file