int make_friends(const char *name1, const char *name2, User *head) {
    User *curr1 = head;
    User *curr2 = head;
    User *store1 = NULL;
    User *store2 = NULL;
    while (curr1 != NULL) {
        if (strcmp(curr1->name, name1) == 0) {
            store1 = curr1;
        }
        else {
            curr1 = curr1->next;
        }
    }
    while (curr2 != NULL) {
        if (strcmp(curr2->name, name2) == 0) {
            store2 = curr2;
        }
        else {
            curr2 = curr2->next;
        }
    }
    if (store1 == NULL || store2 == NULL) {
        return 4; 
    }
    else if (store1 == store2) {
        return 3;
    }
    else if (store1->friends[10] != NULL || store2->friends[10] != NULL) {
        return 2;
    }
    else {
        
    }

//      *   - 0 on success.
//  *   - 1 if the two users are already friends.
    return 0;
}
how do i return 1 if the two users are already friends?