#include <bits/stdc++.h>
using namespace std;

int main() {
	int N, k, a;
	
	cin >> N;
	
	k = 1;
	a = 9 % N;
	while(a != 0) {
		k++;
		a = (10 * a + 9) % N;
	}
	
	cout << k << endl;
}