C1- Lecture Problem 2

Given an integer $n$ as input, write a program to evaluate and print the sum of all the digits present in $n$ ###Input: The only line in the input contains a single integer $n$ ###Output: Output a single integer containing the sum of digits of $n$ ###Constraints - $1 \leq n \leq 10^{18}$ ###Subtasks - 50 points : $1 \leq n \leq 10^9$ - 50 points : $1 \leq n \leq 10^{18}$ ###