Assignment name: thread_basics  
Expected files: thread_basics.c  
Allowed functions: memset, printf, malloc, free, write, pthread_create,
pthread_detach, pthread_join, usleep, gettimeofday
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Create a program that launches 2 threads. Each thread should print its ID and a different message.
The main program must wait for both threads to finish before exiting.

Thread 1 should print: "Thread 1: Hello from thread 1"  
Thread 2 should print: "Thread 2: Hello from thread 2"

The program must accept as an argument the number of messages each thread should print.

Usage: `./thread_basics 5`

Hint: This exercise teaches you the basics of pthread_create and pthread_join.
Remember to check the return values of pthread functions.
Use a structure to pass arguments to threads.