#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < n; i++)
using ll = long long;
using graph = vector<vector<int>>;

const ll mod = 1000000007;
const int INF = 1001001001;

int main(){
    ll n; cin >> n;
    ll ok = n+1, ng = 0;
    while(ok - ng > 1){
        ll mid = (ng + ok) / 2;
        auto f = [&](){
            for(int i = 2; i <= 10; i++){
                ll tmp = n, cnt = 0;
                while(tmp > 1){
                    tmp /= i;
                    cnt++;
                }
                //cout << i <<" " << cnt << endl;
                if(cnt * i <= mid) return true;
                else continue;
            }
            return false;
        };
        if(f()) ok = mid;
        else ng = mid;
    }
    cout << ok << endl;
}