#include <iostream>

using namespace std;

int number, num_save, sum = 0;

// This assignment is worth 5 points
// -2 if the math library was used

int main()
{
	cout << "Enter a number: ";
	cin >> number;
	cin.ignore();

	num_save = number;

	while(number > 0)
	{
		sum += number % 10;
		number /= 10;
	}

	cout << "Digit sum of " << num_save << " is " << sum << ".\n";

	return 0;
}