/**
 * sum - Sum all of integers read from input.
 */

// +---------+--------------------------------------------------------
// | Headers |
// +---------+

#include <stdio.h>	// For scanf, printf


// +------+-----------------------------------------------------------
// | Main |
// +------+

int
main ()
{
  int sum = 0;  // The sum of the numbers read so far.
  int num;      // The next number we've read
  int check;    // The result of scanf

  // Read all the numbers and add them to our sum
  while ((check = scanf ("%d", &num)) != EOF)
    {
      // Special case: Failed to read a number and failed to reach
      // end of file.
      if (check == 0)
        {
          printf ("Invalid input: '%c'\n", getchar ());
          continue;
        }
      sum += num;
    } // while

  // Print out the result
  printf ("%d\n", sum);

  // And we're done
  return 0;
} // main