/*By P'Yutaka 
nest loop */
#include <stdio.h>

void plus2(int num, int num2);
void main()
{
	int num;

	printf("input:");
	scanf("%d",&num);

	plus2(num%2 +1,num);

}

void plus2(int num, int num2)
{
	if(num < num2 -2)
	{
		printf("%d\n", num);
		plus2(num+2,num2);
	}
	printf("%d\n", num);
}