#include <stdio.h>

int AllSum(int n);

int main()
{
  int in;                        /* Input value                 */
  int sum;                       /* Value of 1+2+3+..+n         */
  
  do {
    printf("Input a number: ");
    scanf("%d", &in);
    
    if (in > 0) { 
      sum = AllSum(in);
      printf("The AllSum of %d is %d\n", in, sum);
    }
  } while (in > 0);
}


int AllSum(int n)
{
  int i;                         /* Iteration count             */
  int result;                    /* Result to be returned       */
								    
  for (i = 1; i <= n; i++)       /* This loop calculates sum    */
    result = result + i;					    
  								    
  return result;                 /* Return to caller            */
}