#include <stdlib.h>
#include <stdio.h>

int main(void) {
  int n; /* the number being reduced to its digital root */
  int nn; /* temporary variable for the calculation */
  int orign; /* variable to keep the value of n as given by user */

  printf("Please enter a non-negative integer: ");
  if ( scanf("%d",&n) != 1  ||  n < 0 ) {
    printf("Bad input!\n");
    return EXIT_FAILURE;
  }

  /* Complete the program to compute the digital root. The digital root
     should be left in  n  , and the original value of  n  in  orign.
  */

  /* BEGIN ANSWER -- do not delete this line */

  // ADD YOUR CODE HERE

  /* END ANSWER -- do not delete this line */

  printf("The digital root of %d is %d\n",orign,n);
  return EXIT_SUCCESS;
}