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

struct list
{
    int val;
    struct list *next;
};

void tofront(struct list **ppl)
{
    struct list *tmp = *ppl;
    int n = 0;

    while(tmp != NULL)
    {
        ++n;
        tmp = tmp->next;
    }

    struct list *tmp1 = *ppl;
    int it = 0;

    while (it < n - (n / 3) - 1)
    {
        tmp1 = tmp1->next;
        ++it;
    }

    struct list *tmp2 = tmp1->next;
    tmp1->next = NULL;
    tmp->next = *ppl;
    *ppl = tmp1;
}

int main(void)
{
    struct list *head = NULL;
    struct list *tmp = (struct list*)malloc(sizeof(struct list));
    tmp->val = 1;
    tmp->next = head;
    head = tmp;

    struct list *p = head;

    int res = tofront(&head);
    printf("%d", res);

    return 0;
}