Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
List of longest caves
Table title:
List
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > System </th><th colspan=1 rowspan=1 > Length </th><th colspan=1 rowspan=1 > Location </th><th colspan=1 rowspan=1 > Discovery </th><th colspan=1 rowspan=1 > Associated parks, protected areas </th></tr>
<tr> <td colspan=1 rowspan=1 > Mammoth Cave </td><td colspan=1 rowspan=1 > 651.8 km (405.0 mi) </td><td colspan=1 rowspan=1 > near Brownsville, Kentucky, United States </td><td colspan=1 rowspan=1 > 1791 </td><td colspan=1 rowspan=1 > Mammoth Cave National Park, also a World Heritage Site and International Biosphere Reserve </td></tr>
<tr> <td colspan=1 rowspan=1 > Sistema Sac Actun / Sistema Dos Ojos </td><td colspan=1 rowspan=1 > 360.5 km (224.0 mi) </td><td colspan=1 rowspan=1 > near Tulum, Quintana Roo, Mexico </td><td colspan=1 rowspan=1 > 1987 </td><td colspan=1 rowspan=1 > none </td></tr>
<tr> <td colspan=1 rowspan=1 > Jewel Cave </td><td colspan=1 rowspan=1 > 324.9 km (201.9 mi) </td><td colspan=1 rowspan=1 > near Custer, South Dakota, United States </td><td colspan=1 rowspan=1 > 1900 </td><td colspan=1 rowspan=1 > Jewel Cave National Monument </td></tr>
<tr> <td colspan=1 rowspan=1 > Sistema Ox Bel Ha </td><td colspan=1 rowspan=1 > 270.2 km (167.9 mi) </td><td colspan=1 rowspan=1 > near Tulum, Quintana Roo, Mexico </td><td colspan=1 rowspan=1 > 1996 </td><td colspan=1 rowspan=1 > southern parts in Sian Ka'an Biosphere Reserve </td></tr>
<tr> <td colspan=1 rowspan=1 > Shuanghedong Cave Network </td><td colspan=1 rowspan=1 > 257.4 km (159.9 mi) </td><td colspan=1 rowspan=1 > Guizhou, China </td><td colspan=1 rowspan=1 > 1988 </td><td colspan=1 rowspan=1 > Suiyang Shuanghedong National Geopark </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Optymistychna Cave </td><td colspan=1 rowspan=1 > 257.0 km (159.7 mi) </td><td colspan=1 rowspan=1 > near Korolivka, Ukraine </td><td colspan=1 rowspan=1 > 1966 </td><td colspan=1 rowspan=1 > Dnistrovskyy Canion </td></tr>
<tr> <td colspan=1 rowspan=1 > Wind Cave </td><td colspan=1 rowspan=1 > 241.6 km (150.1 mi) </td><td colspan=1 rowspan=1 > near Hot Springs, South Dakota, United States </td><td colspan=1 rowspan=1 > 1881 </td><td colspan=1 rowspan=1 > Wind Cave National Park </td></tr>
<tr> <td colspan=1 rowspan=1 > Clearwater Cave System </td><td colspan=1 rowspan=1 > 227 km (141.1 mi) </td><td colspan=1 rowspan=1 > near Miri, Sarawak, Malaysia </td><td colspan=1 rowspan=1 > 1978 </td><td colspan=1 rowspan=1 > Gunung Mulu National Park, also a World Heritage Site </td></tr>
<tr> <td colspan=1 rowspan=1 > Lechuguilla Cave </td><td colspan=1 rowspan=1 > 222.6 km (138.3 mi) </td><td colspan=1 rowspan=1 > near Carlsbad, New Mexico, United States </td><td colspan=1 rowspan=1 > 1900 </td><td colspan=1 rowspan=1 > Carlsbad Caverns National Park </td></tr>
<tr> <td colspan=1 rowspan=1 > Fisher Ridge Cave System </td><td colspan=1 rowspan=1 > 208.8 km (129.7 mi) </td><td colspan=1 rowspan=1 > near Brownsville, Kentucky, United States </td><td colspan=1 rowspan=1 > 1981 </td><td colspan=1 rowspan=1 > partly within Mammoth Cave National Park </td></tr>
<tr> <td colspan=1 rowspan=1 > Hölloch </td><td colspan=1 rowspan=1 > 201.9 km (125.5 mi) </td><td colspan=1 rowspan=1 > Muotathal, Switzerland </td><td colspan=1 rowspan=1 > 1875 </td><td colspan=1 rowspan=1 > none </td></tr>
</table>
Question:
How long is the Optymistychna Cave compared to other caves in the world?
Answer:
Optymistychna Cave is one of the longest cave in the world, after Mammoth Cave, Sistema Sac Actun, Jewel Cave, and Sistema Ox Bel Ha.