#21. Write a Python Program to find sum of digits of a number

number = input("Enter a Number: ")

sum = 0

if int(number) < 0 :
    print("Please enter a valid positive number")

else: 
    for i in range(0,len(number)):

        sum += int(number[i])

        i += 1
        
    print("The sum of digits is:", sum)