#define _USE_MATH_DEFINES
#include<iostream>
#include<vector>
#include<algorithm>
#include<cmath>
#include<string>
#include<iomanip>
#include<numeric>
#include<queue>
#include<deque>
#include<stack>
#include<set>
#include<map>
#include<random>
using namespace std;
typedef long long ll;
const int mod=998244353;
int main(){
	ll a;
	cin>>a;
	if(a==5)
		cout<<5<<endl,exit(0);
	cout<<min((ll)ceil(log(a)/log(2))*2,(ll)ceil(log(a)/log(3))*3)<<endl;
}