// p04_02.cpp: sum of the decimal digits of an integer.
#include <iostream>
using namespace std;

int digitsum(int n) {
 int sum = 0;
 n = abs(n);
 while (n > 0) {
  sum += n % 10;
  n /= 10;
 }
 return sum;
}

int main() {
 int k;
 cout << "Enter an integer: ";
 cin >> k;
 cout << "The sum of its decimal digits is "
      << digitsum(k) << ". \n";
 return 0;
}