
int main()
{
	int n;
	scanf("%d",&n);
	int i,j;
	int count=0;
	int a[50000];
	int flag[50000];
	for(i=1;2*i+1<=n;i++)
	{
		flag[i]=1;
		for(j=2;j<=i+1;j++)
		{
			if((2*i+1)%j==0)
				flag[i]=flag[i]*0;
			else
				flag[i]=flag[i]*1;
		}
		if(flag[i]==1)
		{
		
			a[count]=2*i+1;
			count++;
		}
	}
	if(n<=4)
		printf("empty");
	for(i=0;i<count-1;i++)
	{
		if(a[i]==a[i+1]-2)
			printf("%d %d\n",a[i],a[i+1]);
	}
	return 0;

}
