# Given an integer num, repeatedly add all its digits until the result has only one digit, and return it.


# Example 1:

# Input: num = 38
# Output: 2
# Explanation: The process is
# 38 --> 3 + 8 --> 11
# 11 --> 1 + 1 --> 2 
# Since 2 has only one digit, return it.

# Example 2:

# Input: num = 0
# Output: 0

class Solution:
    def addDigits(self, num: int) -> int:
        while num > 9:
            sum = 0
            while num != 0:
                sum += num % 10
                num = num//10
                
            num = sum
        return num