### CONTEXT (Previous Events):
<user_input timestamp="4990.783403">OD</user_input>
<system_output timestamp="4990.804244"/>
<user_input timestamp="4990.824538">OD</user_input>
<system_output timestamp="4990.844651"/>
<user_input timestamp="4990.865411">OD</user_input>
<user_input timestamp="4990.885844">OD</user_input>
<system_output timestamp="4990.88649"/>
<system_output timestamp="4990.906678"/>
<user_input timestamp="4990.928621">OD</user_input>
<system_output timestamp="4990.947034"/>
<user_input timestamp="4990.969617">OD</user_input>
<system_output timestamp="4990.987714"/>
<user_input timestamp="4991.009887">OD</user_input>
<system_output timestamp="4991.029013"/>

### TARGET LINE (Extract and Classify THIS Timestamp):
<user_input timestamp="4991.051801">OD</user_input>

Answer: 4991.051801, old event