#include<stdio.h>
#include<string.h>
#include<math.h.>
#include<stdlib.h>
#define NUll 0
#define LEN sizeof(struct student)
struct student {  
      long int num;
      float  score; 
     struct student *next;
};
  struct student  *creat(void);
  int n;
void main(){
   struct student *head;
	head = creat();
}
struct student  *creat( ){
	struct student *head;
	struct student *p1,*p2;
	n=0;
	p1=p2=(struct student*)malloc(LEN);
	scanf("%ld,%f",&p1->num,&p1->score);
	head=NULL;
	while(p1->num!=0){
		n=n+1;
		if(n==1)head=p1;
		else p2->next=p1;
		p2=p1;
		p1=(struct student*)malloc(LEN);
		scanf("%ld,%f",&p1->num,&p1->score);
	}
	p2->next=NULL;
	return(head);
}