Calculate the sum of the digits in an integerΒΆ

Calculate the sum of the digits in an integer.
num = int(input("Input a four digit numbers: "))

x  = num //1000
x1 = (num - x*1000)//100
x2 = (num - x*1000 - x1*100)//10
x3 = num - x*1000 - x1*100 - x2*10

print("The sum of digits in the number is", x+x1+x2+x3)

Output:

Input a four digit numbers: 5245
The sum of digits in the number is 16