int main()
{
    int total_number_of_shelves;
    scanf("%d", &total_number_of_shelves);
    
    total_number_of_books = calloc(total_number_of_shelves, sizeof(int));
    total_number_of_pages = calloc(total_number_of_shelves, sizeof(int*));
    
    int total_number_of_queries;
    scanf("%d", &total_number_of_queries);
    
    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 size, x, y;
            scanf("%d %d", &x, &y);
            
            total_number_of_books[x] += 1;
            size = total_number_of_books[x];
            
            total_number_of_pages[x] = realloc(total_number_of_pages[x], size * sizeof(int));
            
            total_number_of_pages[x][size - 1] = y;

        }

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

/*
 * This stores the total number of books in each shelf.
 */
int* total_number_of_books;

/*
 * This stores the total number of pages in each book of each shelf.
 * The rows represent the shelves and the columns represent the books.
 */
int** total_number_of_pages;

int main()
{
    int total_number_of_shelves;
    scanf("%d", &total_number_of_shelves);
    
    // Initialize memory for total_number_of_books
    total_number_of_books = (int*) calloc(total_number_of_shelves, sizeof(int));
    
    // Initialize memory for total_number_of_pages
    total_number_of_pages = (int**) calloc(total_number_of_shelves, sizeof(int*));
    
    int total_number_of_queries;
    scanf("%d", &total_number_of_queries);
    
    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.
             * This query is to add books to a shelf.
             */
            int x, y;
            scanf("%d %d", &x, &y);
            
            // Increase the number of books on the shelf
            *(total_number_of_books + x) += 1;
            
            // Reallocate memory for the shelf if necessary
            if (*(total_number_of_books + x) == 1) {
                *(total_number_of_pages + x) = (int*) malloc(sizeof(int));
            } else {
                *(total_number_of_pages + x) = (int*) realloc(*(total_number_of_pages + x), (*(total_number_of_books + x)) * sizeof(int));
            }
            
            // Add the number of pages of the new book
            *(*(total_number_of_pages + x) + (*(total_number_of_books + x) - 1)) = y;
            

        } 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));
        }
    }

    if (total_number_of_books) {
        free(total_number_of_books);
    }
    
    for (int i = 0; i < total_number_of_shelves; i++) {
        if (*(total_number_of_pages + i)) {
            free(*(total_number_of_pages + i));
        }
    }
    
    if (total_number_of_pages) {
        free(total_number_of_pages);
    }
    
    return 0;
}