#returns the sum of num1 and num2
def add(num1, num2):
	return num1 + num2
	#returns the sub of num1 and num2
def	sub(num1, num2):
	return num1 - num2
	#returns the multi of num1 and num2
def multi(num1, num2):
	return num1 * num2
	#returns the div of num1 and num2
def div(num1, num2):
	return num1 / num2

def main():
	exitInput = False
	while not exitInput:
			correctInput = False
			while not correctInput:
				try:
					num1 = int(input("Enter first number: "))
					num2 = int(input("Enter second number: "))
					operation = int(input("What you want to do: 1 to add , 2 to subtract , 3 to multiply , 4 to divide. Enter number: "))
					correctInput = True
				except:
					print("Invalid operation! Try again.")
			if (operation == 1):
				print("Result:")
				print(add(num1, num2))
			elif (operation == 2):
				print("Result:")
				print(sub(num1, num2))
			elif (operation == 3):
				print("Result:")
				print(multi(num1, num2))
			elif (operation == 4):
				print("Result:")
				print(div(num1, num2))
			else:
				print("You must enter valid operation")
			wtfInput = False
			while not wtfInput:
				try:
					exitingNote = int(input('Do u want some more? Type 1 for "Yes" or 2 for "No": '))
					if (exitingNote == 1):
						print('Ok')
						exitInput = False
						break
					elif (exitingNote == 2):
						print('Bye bye!')
						continue
					else:
						print("Wrong")
						wtfInput = False
				except:
					print("wtf?")
					wtfInput = False
main()