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

struct node {
    struct node *next;
    int          data;
};


// Given two linked lists, 
// count the number of  nodes at the same index in both lists
// which their values are divisible by 5
// For example:
// 2->1->40->X
// 1->2->30->4->100->X
// Would print out 1
// because both 40 and 30 at the same index (2) are divisible by 5

int count_divisible(struct node *head1, struct node *head2) {
    // PUT YOUR CODE HERE
    struct node *tmp1 = head1;
    struct node *tmp2 = head2;
    int count = 0;
    while (tmp1 != NULL && tmp2 != NULL) {
        if (tmp1->data % 5 == 0 && tmp2->data % 5 == 0) {
            count++;
        }
        tmp1 = tmp1->next;
        tmp2 = tmp2->next;
    }

    return count;

}


struct node *strings_to_list(int len, char *strings[]);

// DO NOT CHANGE THIS MAIN FUNCTION
int main(int argc, char *argv[]) {
    // create two linked lists from command line arguments
    int dash_arg = argc - 1;
    while (dash_arg > 0 && strcmp(argv[dash_arg], "-") != 0) {
        dash_arg = dash_arg - 1;
    }
    struct node *head1 = strings_to_list(dash_arg - 1, &argv[1]);
    struct node *head2 = strings_to_list(argc - dash_arg - 1, &argv[dash_arg + 1]);

    printf("%d\n", count_divisible(head1, head2));

    return 0;
}


// DO NOT CHANGE THIS FUNCTION
// create linked list from array of strings
struct node *strings_to_list(int len, char *strings[]) {
    struct node *head = NULL;
    for (int i = len - 1; i >= 0; i = i - 1) {
        struct node *n = malloc(sizeof (struct node));
        assert(n != NULL);
        n->next = head;
        n->data = atoi(strings[i]);
        head = n;
    }
    return head;
}