ONP

def priority(oper)
  case oper
    when '*','/'
    2
    when '^'
    3
    when '('
    0
    when nil
    -1
  else
    1
  end
end

def onpize(input)
  input = input.split(//)
  out = ''
  stack = []

  while !input.empty?
    elem = input.shift

    if 'abcdef0123456789'.include? elem
      out << elem
    elsif '+-*/^'.include? elem
      while priority(stack.last) >= priority(elem)
        puts [priority(elem), priority(stack.last)].join
        out << stack.pop
      end

      stack.push(elem)
    elsif elem == '('
      stack.push(elem)
    elsif elem == ')'
      while (elem2 = stack.pop) != '('
        out << elem2
      end
    end
  end

  while !stack.empty?
    out << stack.pop
  end

  puts
  out
end

puts onpize(gets.chomp)
gets