diff --git a/Lesson_3/We know/bank_card.py b/Lesson_3/We know/bank_card.py
new file mode 100644
index 0000000..a8cd975
--- /dev/null
+++ b/Lesson_3/We know/bank_card.py	
@@ -0,0 +1,37 @@
+def validateLength(number):
+	if len(number) < 13 or len(number) > 16 or len(number) == 14:
+		return False
+	return True
+
+def validateLuhn(number):
+	even = False
+	evenDigits = ""
+	evenSum = 0
+	oddSum = 0
+	for i in reversed(range(len(number))):
+		if even:
+			evenDigits += str(int(number[i]) * 2)
+		else:
+			oddSum += int(number[i])
+		even = not even
+
+	for i in range(len(evenDigits)):
+		evenSum += int(evenDigits[i])
+
+	if (evenSum + oddSum) % 10 == 0:
+		return True
+	return False
+
+number = input("Number: ")
+if validateLength(number) and validateLuhn(number):
+	if len(number) == 13 or len(number) == 16 and number[0] == "4":
+		print("VISA")
+	elif len(number) == 16 and number[0] == "5" and int(number[1]) >= 1 and int(number[1]) <= 5:
+		print("MASTERCARD")
+	elif len(number) == 15 and number[0] == "3" and number[1] == "4" or number[1] == "7":
+		print("AMEX")
+	else:
+		print("INVALID")
+else:
+	print("INVALID")
+