Add an integer between 0 to 999

Write a program that reads an integer between 0 to 999 and adds all the digits in the integer.

#include <stdio.h>
#include <conio.h>

int main()
{
    int count = 0, num = 0;
    int reminder = 0, sum = 0;
    int stop = 0;

    while (stop != -1)
    {
        printf("Enter an integer: ");
        scanf_s("%d", &num);
      
        printf("\n After operation:\n");
        printf("reminder num\n");
        printf("--------- ---\n");
      
        while(num != 0)
        {
            reminder = num % 10;    /* get the reminder (digits) by dividing by 10*/
            sum = sum + reminder;  /* sum up the reminder*/
            num = num / 10;
            printf("%d %d\n", reminder, num); // let see current value of num and
                                                           // reminder...
        }
        printf("\n");
        printf("The sum of digits is %d\n", sum);   /* print the sum of the digits */
        sum = 0;
        printf("More? -1 to stop, other to continue: ");
        scanf_s("%d",&stop);
    }
    return 0;
}