N = gets.to_i
ans = N

2.upto(Math.log2(N).floor) do |j|
  ok = 2
  ng = N
  while (ok - ng).abs >= 2
    x = (ok + ng) / 2

    if x ** j <= N
      ok = x
    else
      ng = x
    end
  end

  k = N - ok ** j
  v = ok + j + k
  ans = v if ans > v
end

puts ans