#include <bits/stdc++.h>
using namespace std;
int main(){
  long long n;
  cin >> n;
  long long ans = n + 1;
  for (int i = 1; i <= 60; i++){
    long long tv = 0, fv = n + 1;
    while (fv - tv > 1){
      long long mid = (tv + fv) / 2;
      long long P = 1;
      for (int j = 0; j < i; j++){
        if (n / mid < P){
          P = n + 1;
          break;
        }
        P *= mid;
      }
      if (P <= n){
        tv = mid;
      } else {
        fv = mid;
      }
    }
    long long P = 1;
    for (int j = 0; j < i; j++){
      P *= tv;
    }
    ans = min(ans, tv + i + (n - P));
  }
  cout << ans << endl;
}