# frozen_string_literal: true

class Integer
  def to_number
    self >= 48 && self <= 57 ? self - 48 : self - 55
  end
end

class Array
  def to_integer(base)
    size
      .times
      .to_a
      .reverse
      .map { base**_1 }
      .zip(self)
      .filter { _1 && _2 }
      .map { _1 * _2 }
      .sum
  end
end

class String
  def parse
    codepoints = chars.map { _1.ord.to_number }
    base = codepoints.max + 1
    codepoints.to_integer(base)
  end
end

def solve
  V.map { _1.parse }.min
end

N = gets.to_i
V = N.times.map { gets.chomp }

puts solve