N = gets.to_i

def f(d, l, x)
  return -Float::INFINITY if d >= x

  num = 0
  n = 1

  l.times do
    num += d * n
    n *= x
  end

  num
end

L = N.to_s(2).size
ans = Float::INFINITY

L.downto(1) do |l|
  1.upto(9) do |d|
    ng = 1
    ok = N + 1

    while (ok - ng).abs >= 2
      x = (ok + ng) / 2

      if N <= f(d, l, x)
        ok = x
      else
        ng = x
      end
    end

    if f(d, l, ok) == N && ans > ok
      ans = ok
    end
  end
end

puts ans