#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <map>
#include <set>
#include <queue>
#include <iomanip>
#include <cstring>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i,n) for (int i = 0; i < int(n);i++)

int main(){
  ll n;
  cin >> n;
  ll ans = 1e18;
  for (ll i = 1; i < 1e7;i++){
    ll x = i;
    ans = min(ans,i+n-1);
    if (i == 1) continue;
    ll j = 1;
    while(x <= n){
      ans = min(ans,i+j+n-x);
      j++;
      x*=i;
    }
  }
  cout << ans << endl;
  return 0;
}