C

int main() { int sum =0; FILE * ptr; ptr = fopen("d:students. "," "); if (ptr ==NULL){ ("file does not exist!!"); exit(0); }

int main() {

int sum =0;
FILE * ptr;
ptr = fopen("d:students.________","___________");

if (ptr ==NULL){
 _______________("file does not exist!!");
 exit(0);
}