int total_number_of_shelves;
    scanf("%d", &total_number_of_shelves);
    
    int total_number_of_queries;
    scanf("%d", &total_number_of_queries);
    
    total_number_of_books = (int *) calloc(total_number_of_shelves,sizeof(int));
    total_number_of_pages = (int **) calloc(total_number_of_shelves,sizeof(int *));
    
    while (total_number_of_queries--) {
        int type_of_query;
        scanf("%d", &type_of_query);
        
        if (type_of_query == 1) {
            /*
             * Process the query of first type here.
             */
            int x, y;
            scanf("%d %d", &x, &y);
            int bIS = *(total_number_of_books + x);
            *(total_number_of_pages + x) = (int*)realloc(*(total_number_of_pages+x),sizeof(int)*(bIS+1));
            *(*(total_number_of_pages+x)+bIS) = y;
            *(total_number_of_books + x) += 1; // the address the Incremented by 1 so pointing to next address of total_number_of_page[1]

        } else if (type_of_query == 2) {
            int x, y;
            scanf("%d %d", &x, &y);
            printf("%d\n", *(*(total_number_of_pages + x) + y));
        } else {
            int x;
            scanf("%d", &x);
            printf("%d\n", *(total_number_of_books + x));
        }
    }