input: Write a python function to parse the given HTML string and extract the names and ages from the table.
  assert parse_html("<html><head></head><body><table><tr><th>Name</th><th>Age</th><th>City</th></tr><tr><td>John</td><td>20</td><td>New York</td></tr><tr><td>Jane</td><td>25</td><td>San Francisco</td></tr></table></body></html>") == [('John', 20), ('Jane', 25)]
  assert parse_html("<html><head></head><body><table><tr><th>Name</th><th>Age</th><th>City</th></tr><tr><td>John</td><td>20</td><td>New York</td></tr></table></body></html>") == [('John', 20)]
  assert parse_html("<html><head></head><body><table><tr><th>Name</th><th>Age</th><th>City</th></tr></table></body></html>") == []
output: def parse_html(html):
      from bs4 import BeautifulSoup
      
      soup = BeautifulSoup(html, 'html.parser')
      table = soup.find('table')
      rows = table.find_all('tr')[1:]  # Skip the header row
      result = []
      
      for row in rows:
          cols = row.find_all('td')
          name = cols[0].text
          age = int(cols[1].text)
          result.append((name, age))
      
      return result