class HTMLElement:
    def __init__(self, tag_name):
        self.tag_name = tag_name
        self.children = []
        self.attrs = {}
    def add_child(self, element):
        self.children.append(element)
        return self
    def add_children(self, *elements):
        self.children.extend(elements)
        return self
    def set_attrs(self, **kwargs):
        self.attrs = kwargs
        return self
    def _start(self):
        if self.attrs:
            attrs = ' '.join(f'{key}="{value}"' for key,value in self.attrs.items())
            return f'<{self.tag_name} {attrs}>'
        else:
            return f'<{self.tag_name}>'
    def _end(self):
        return f'</{self.tag_name}>'

class SelfClosedTag(HTMLElement):
    def format(self):
        return f'\n{self._start()}'

class ClosedTag(HTMLElement):
    def format(self):
        content = ''.join(ch.format() for ch in self.children)
        mid = f'{content}' if self.children else ''
        return f'\n{self._start()}{mid}\n{self._end()}'

class Text:
    def __init__(self, text):
        self.text = text
    def format(self):
        return self.text

###

form = ClosedTag('form')
for i in range(3):
    form.add_child(SelfClosedTag('input').set_attrs(type='radio', name='radio'))
    form.add_child(SelfClosedTag('br'))

sel = ClosedTag('select')
for i in range(4):
    sel.add_child(ClosedTag('option').add_child(Text(f'Choice{i}')))

form.add_children(
    sel,
    SelfClosedTag('br'),
    ClosedTag('input').set_attrs(type='submit'),
    SelfClosedTag('br')
)

html = ClosedTag('html').add_children(
    ClosedTag('head').add_children(
    ),
    ClosedTag('body').add_children(
        form,
        SelfClosedTag('br'),
        ClosedTag('a').set_attrs(href='www.microsoft.com').add_children(
            ClosedTag('div').add_children(
                Text('How was it?')
            )
        )
    )
)

print(html.format())