cards.c

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

int main()
{
  char card_name[3];
  int count = 0;

  do
  {
    puts("Enter the card_name: ");
    scanf("%2s", card_name);

    int val = 0;

    switch (card_name[0])
    {
    case 'K':
    case 'Q':
    case 'J':
      val = 10;
      break;
    case 'A':
      val = 11;
      break;
    case 'X':
      continue;
    default:
      val = atoi(card_name);

      if ((val < 1 || val > 10))
      {
        puts("Value out of range!");
        continue;
      }

      break;
    }

    /* Check if the value is 3 to 6 */
    if (val > 2 && val < 7)
    {
      count++;
    }
    /* Otherwise check if the card was 10, J, Q, or K */
    else if (val == 10)
    {
      count--;
    }

    printf("Current count: %i\n", count);
  } while (card_name[0] != 'X');

  return 0;
}