Ones/문보창

~cpp 
// no10127 - Ones
#include <iostream>
using namespace std;

void main()
{
	int n, temp, reminder, i, j;
	while (cin >> n)
	{
		reminder = 0;
		for (i=0; ;i++)
		{
			temp = 1;
			for (j=0; j<i; j++)
			{
				temp *= 10;
				if (temp >= n)
					temp %= n;
			}
			reminder += temp;
			if (reminder % n == 0)
				break;
		}
		cout << i+1 << endl;
	}
}