#include <stdio.h>
struct count_to_n_data;
struct count_to_n_data
{
	int n;
	int c;
};
int count_to_three(int pc);
int count_to_n(int pc, void *data);
int main(void);
int count_to_three(int pc)
{
	switch(pc)
	{
	case 0:	printf("1\n");
		return 1;
	case 1:	printf("2\n");
		return 2;
	case 2:	printf("3\n");
		return 3;
	case 3:	;
	}
	return -1;
}
int count_to_n(int pc, void *data)
{
	count_to_n_data *d = (count_to_n_data *)data;
	switch(pc)
	{
	case 0:	d->c = 1;
		while(d->c <= d->n)
		{
			printf("%d\n", d->c);
			++ (d->c);
			return 1;
	case 1:		;
		}
	}
	return -1;
}
int main(void)
{
	count_to_n_data d1, d2;
	d1.n = 10;
	d2.n = 15;
	int pc1 = 0;
	int pc2 = 0;
	while(pc1 != -1 || pc2 != -1)
	{
		if(pc1 != -1)
		{
			pc1 = count_to_n(pc1, &d1);
		}
		if(pc2 != -1)
		{
			pc2 = count_to_n(pc2, &d2);
		}
	}
	return 0;
}