diff --git a/sprint_3.py b/sprint_3.py
new file mode 100644
index 0000000..663fdc8
--- /dev/null
+++ b/sprint_3.py
@@ -0,0 +1,82 @@
+class OnlineSalesRegisterCollector:
+
+    def __init__(self):
+        self.__name_items = []
+        self.__number_items = 0
+        self.__item_price = {'чипсы': 50, 'кола': 100, 'печенье': 45, 'молоко': 55, 'кефир': 70}
+        self.__tax_rate = {'чипсы': 20, 'кола': 20, 'печенье': 20, 'молоко': 10, 'кефир': 10}
+
+    @property
+    def get_name_items(self):
+        return self.__name_items
+
+    @property
+    def get_number_items(self):
+        return self.__number_items
+
+    def add_item_to_cheque(self, name):
+        if len(name) != 0 or len(name) < 40:
+            raise ValueError('Нельзя добавить товар, если в его названии нет символов или их больше 40')
+        else:
+            self.__name_items.append(name)
+            self.__number_items += 1
+
+    def delete_item_from_check(self, name):
+        if name in self.__name_items:
+            self.__name_items.remove(name)
+            self.__number_items -= 1
+        else:
+            raise NameError('Позиция отсутствует в чеке')
+
+    def check_amount(self):
+        total = []
+        for i in range(len(self.__name_items)):
+            if self.__name_items[i] in self.__item_price:
+                total.append(self.__item_price.get(self.__name_items[i]))
+        if len(self.__name_items) > 10:
+            return sum(total) - (sum(total) * 10) / 100
+        else:
+            return sum(total) * 0.9
+
+    def twenty_percent_tax_calculation(self):
+        twenty_percent_tax = []
+        for i in range(0, len(self.__name_items)):
+            if self.__name_items[i] in self.__tax_rate:
+                if self.__tax_rate.get(self.__name_items[i]) == 20:
+                    twenty_percent_tax.append(self.__name_items[i])
+        total = []
+        for i in range(0, len(twenty_percent_tax)):
+            if twenty_percent_tax[i] in self.__item_price:
+                total.append(self.__item_price.get(twenty_percent_tax[i]))
+        if len(twenty_percent_tax) > 10:
+            return (sum(total) - (sum(total) * 10) / 100)
+        else:
+            return sum(total)
+
+    def ten_percent_tax_calculation(self):
+        ten_percent_tax = []
+        for i in range(0, len(self.__name_items)):
+            if self.__name_items[i] in self.__tax_rate:
+                if self.__tax_rate.get(self.__name_items[i]) == 20:
+                    ten_percent_tax.append(self.__name_items[i])
+        total = []
+        for i in range(0, len(ten_percent_tax)):
+            if ten_percent_tax[i] in self.__item_price:
+                total.append(self.__item_price.get(ten_percent_tax[i]))
+        if len(ten_percent_tax) > 10:
+            return (sum(total) - (sum(total) * 10) / 100)
+        else:
+            return sum(total)
+
+    def total_tax(self):
+        return OnlineSalesRegisterCollector.ten_percent_tax_calculation() + OnlineSalesRegisterCollector.twenty_percent_tax_calculation()
+
+    @staticmethod
+    def get_telephone_number(telephone_number):
+        if len(str(telephone_number)) > 10:
+            raise ValueError('Необходимо ввести 10 цифр после "+7"')
+        try:
+            float(telephone_number)
+        except ValueError:
+            raise ValueError('Необходимо ввести цифры') from None
+        return f'+7{telephone_number}'