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

void main(int argc, char  *argv[]) {
typedef struct {
      int x;
      int g;
      char z[20];
      } Student;
 Student a1,b1,c1,x;
int op,i,j, count=0;
if( strcmp(argv[1], "-count") == 0) op=1;
else if (strcmp(argv[1], "-grade") == 0) op=2;
else if (strcmp(argv[1], "-name") == 0) op=3;
else op=-1;

char fname[20], lname[20],gg;
 FILE *fp;
 fp=fopen("dat.txt","r");
 if(fp == NULL) {printf("can not open file\n"); exit(1);}
 while ( fread(&a1, sizeof(a1), 1, fp) != 0) {
    //printf("%d    %c    %s\n", a1.x, a1.g, a1.z);
    sscanf(a1.z,"%s%s", fname, lname);
    //printf("----  %s  -----  %s ----\n",fname,lname);
    switch (op) {
	case -1:
       	  printf("No such flag\n");
	break;
	case 1:
	  count++;
	break;
	case 2:
	  sscanf(argv[2],"%c",&gg);
	  if(gg == a1.g) printf("%d\t%s\n",a1.x, a1.z);
	break;
	case 3:
	if( strcmp(fname, argv[2]) == 0)
	   printf("%d\t%s\t%c\n", a1.x, a1.z, a1.g);
	break;
        }
 }

if(count != 0) printf("%d\n",count);

}