#include<stdio.h>
#include<stdlib.h>
#define size 4
struct student
{
    char name[10];
    int num;
int age;
    char addr[10];
}stud[size];
void save()
{
      int i;
      FILE *fp;
      if((fp=fopen("student_list.txt","wb"))==NULL)
      {
          printf("sorry,can not open!!\n");
          exit(0);
      }
      for(i=0;i<size;i++)
      {
         
          if(fwrite(&stud[i],sizeof(struct student),1,fp)!=1)      
          printf("file write wrong\n");
      }
     fclose(fp);
}
void main()
{
    int i;
    for(i=0;i<size;i++)
    {
        scanf("%s%d%d%s",stud[i].name,&stud[i].num,&stud[i].age,stud[i].addr);
    }
    i=0;
    printf("%d",stud[i].num);
    save();
}