// https://atcoder.jp/contests/abc222/submissions/26432513
#include<bits/stdc++.h>
using namespace std;

int pow(long long a,int n,int m){
	long long ans=1;
	a%=m;
	while(n){
		if(n%2)ans=ans*a%m;
		a=a*a%m;
		n/=2;
	}
	return (int)ans;
}

int inv(int a,int b){
	if(a==1)return 1;
	return b+(1-(long long)b*inv(b%a,a))/a;
}

int ord(int a,int m){
	a%=m;
	if(gcd(a,m)!=1)return -1;
	int sq=sqrt(m)+1;
	unordered_map<int,int>mp;
	for(long long s=a,i=1;i<=sq;i++,s=s*a%m)if(mp.find(s)==mp.end())mp[s]=i;
	long long g=inv(pow(a,sq,m),m),x=1;
	for(int k=0;k<=m/sq;k++,x=x*g%m)if(mp.find(x)!=mp.end())return sq*k+mp[x];
	assert(0);
}

void solve(){
	int m;
	cin >> m;
    if(m == 1){
        cout << 1 << endl;
        return;
    }
	cout << ord(10,m) << endl;
}

int main(){
	int n = 1;
	// cin >> n;
	while(n--)solve();
}