int count=0;
/* Merge sort the data. */
void *merge_sort(struct block *my_data) {
    int fd[2];
    pid_t ls_pid,sort_pid;
    // print_block_data(my_data);
    if (my_data->size > 1) {
        struct block left_block;
        struct block right_block;
        left_block.size = my_data->size / 2;
        left_block.first = my_data->first;
        right_block.size = left_block.size + (my_data->size % 2);
        right_block.first = my_data->first + left_block.size;
        //create pipe
        if (count == 0 ){
            count++;
            if (pipe(fd) == -1){
                fprintf(stderr,"pipe failed");
                return 1;
            }
            sort_pid = fork();
            if (sort_pid < 0){
                perror("/nChile 2 fork failed");
                return 1;
            }
            if (sort_pid == 0){
                //I AM PARENT
                merge_sort(&left_block);

            }else{
                //I AM CHILd
                merge_sort(&right_block);
                write(fd[0],&left_block,sizeof(struct block));
            }
        }
        merge_sort(&right_block);
        merge_sort(&left_block);
        if(count == 0){
            read(fd[0],&left_block,sizeof(struct block));
            merge(&left_block, &right_block);
        }
        merge(&left_block, &right_block);
    }
    return NULL;
}