#include <iostream>
#include <cmath>
using namespace std;
int main(){
    long long a;cin>>a;
    long long ans =(long long)sqrt(a)+2+a-(long long)sqrt(a)*(long long)sqrt(a);
    for(int i = 2; 1000001 > i; i++){
        long long nw = 1;
        for(int j = 0; a >= nw; j++){
            if(ans == -1)ans = i+j+a-nw;
            else ans = min(ans,i+j+a-nw);
            nw *= i;
        }
    }
    cout << ans << endl;
}