求三个整数平均数的这个程序为啥总是报如下错误

请问下求三个整数平均数的这个程序为啥总是报如下错误，如何解决呢

num1 = input("Input the first integer：")
num2 = input("Input the second integer：")
num3 = input("Input the third integer：")
average = int((num1 + num2 + num3) / 3)
print('average = ' + average)

Traceback (most recent call last):
  File "D:\Pycharmproject.py", line 71, in 
    average = int((num1 + num2 + num3) / 3)
TypeError: unsupported operand type(s) for /: 'str' and 'int'

在输入的时候就把它转换成整形就行了呀，你在最下面三个本来就是字符串，你还把它们相加，那相当于就是字符串的拼接，你一个字符串在分母上，怎么做除法？有帮助的话采纳一下哦！

num1 =int( input("Input the first integer："))
num2 = int(input("Input the second integer："))
num3 = int(input("Input the third integer："))
average = (num1 + num2 + num3) / 3
print('average = ' + average)

num1 = int(input("Input the first integer："))
num2 = int(input("Input the second integer："))
num3 = int(input("Input the third integer："))
average = (num1 + num2 + num3) / 3
print(f'average = {average}')

num1 = int( input("Input the first integer："))
num2 = int(input("Input the second integer："))
num3 = int(input("Input the third integer："))
average = (num1 + num2 + num3) / 3
print('average = ' + str(average))#输出这里要转字符串才能加