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

void solve(){
	ll N;
	cin>>N;
	ll R=10%N;
	ll an=1;
	while(R!=1){
		an++;
		R=(R*10)%N;
	}	
	cout<<an<<endl;

}

int main(){
	
	cin.tie(nullptr);
	ios::sync_with_stdio(false);

	int T=1;
	// cin>>T;
	while(T--)solve();
}