Z = Array.new(128)
('0' .. '9').each_with_index{|c,i| Z[c.ord] = 1 + i  }
('A' .. 'Z').each_with_index{|c,i| Z[c.ord] = 11 + i }
('a' .. 'z').each_with_index{|c,i| Z[c.ord] = 11 + i }
def max(a,b); a > b ? a : b; end
def min_base(str)
  max(2,Z[str.chars.max_by{|c| Z[c.ord] }.ord])
end

N = gets.to_i
puts N.times.map{ s = gets.chomp; s.to_i(min_base(s)) }.min