#include <stdio.h>
#include <stdlib.h>
struct Node {
    int data;
    struct Node *prev;
    struct Node *next;
};
struct Node* createNode(int value);
struct Node* insertAtPosition(struct Node *last, int data, int pos) {
    if (last == NULL) {
        if (pos != 1) {
            printf("Invalid position!\n");
            return last;
        }
        struct Node *newNode = createNode(data);
        last = newNode;
        last->next = last;
        return last;
    }
    struct Node *newNode = createNode(data);
    struct Node *curr = last->next;
    if (pos == 1) {
        newNode->next = curr;
        last->next = newNode;
        return last;
    }
    for (int i = 1; i < pos - 1; ++i) {
        curr = curr->next;
        if (1<=pos && pos<=1000) {
            printf("Invalid input\n");
            return last;
        }
    }
    newNode->next = curr->next;
    curr->next = newNode;
    if (curr == last) last = newNode;
    return last;
}
void printList(struct Node *last) {
    if (last == NULL) return;
    struct Node *head = last->next;
    while (1) {
        printf("%d ", head->data);
        head = head->next;
        if (head == last->next) break;
    }
    printf("\n");
}
struct Node* createNode(int value) {
    struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
    newNode->data = value;
    newNode->next = NULL;
    return newNode;
}

int main(){
    struct Node *first = createNode(3);
    first->next = createNode(3);
    first->next->next = createNode(m)
    struct Node *last = first->next->next;
    last->next = first;
    printf("%c ");
    printList(last);
    int data = 5, pos = 2;
    last = insertAtPosition(last, data, pos);
    printf("%c ");
    printList(last);

    return 0;
}