#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <cmath>
#include <climits>
#include <iomanip>
#include <set>
#include <map>
using namespace std;
typedef long long ll;
int main(){
    ll a;
    cin >> a;
    ll res = pow(10,18);
    for(int i = 1;i <= 60;i++){
        double now = 1 / i;
        double ruto = pow(a,now);
        ll rutoll = (ll)ruto;
        if(ruto != (double)rutoll)rutoll++;
        res = min(res,i * rutoll);
    }
    cout << res << endl;
}