#include <bits/stdc++.h>
using namespace std;
int main(){
    long long n;
    cin >> n;
    long long ans = n;
    for(long long i = 2; i <= 1000000; i++){
        long long t = i;
        int cnt = 1;
        while(t <= n / i){
            t *= i;
            cnt++;
        }
        ans = min(ans, i + cnt - t + n);
    }
    cout << ans << endl;
}