#include <stdio.h>

#include <ctype.h>

void main()

{

  FILE *fp;

  char sf[50], c;

  long count = 0;

  printf("

Nhap vao ten tap tin : ");

  scanf("%s", sf);

  if ((fp = fopen(sf, "r")) == NULL)

    fprintf(stderr, "

Khong the mo tap tin %s", sf);

  else

  {

     while ((c = fgetc(fp)) != EOF)

       if (isalpha(c))

         count++;

     printf("

So ky tu trong %s la %ld", sf, count);

  }

  getch();

}