#include <stdio.h>
#include <unistd.h>
#include <pthread.h>
#include <assert.h>

void *thread_start(void *arg) {
	int n = (int) *((int*)arg);
	sleep(1);
	for (int i = 0; i < n; i++) {
		fprintf(stdout, "X "); 
		fflush(stdout);
	}
	pthread_exit((void*)&n);
}

int main() {
	pthread_t tid;
	void *r;
	int n = 500;

	assert(pthread_create(&tid, NULL, thread_start, (void*) &n)==0);
	for (int i = 0; i < 700; i++) {
		fprintf(stdout, "Y "); 
		fflush(stdout);
	}
	assert(pthread_join(tid, &r) == 0);
	return 0;
}