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