北大OJ2551

#include<stdio.h>
int main()
{
	int n,i,count;
	while(scanf("%d",&n)!=EOF)
	{
		i=1;count=1;
		while(i%n!=0)
		{
			i=(i%n)*10+1;
			count++;
		}
		printf("%d\n",count);
	}
	return 0;
}