June 14, NAME_1 transited the Luzon Strait westbound; Participated in a PHOTOEX with the RSS Intrepid (FFS 69) on June 17; Transited the Strait of Singapore on June 18; Transited the Malacca Strait northbound from June 18-19.
Extract the following items only from the news:
    - date
    - Subject name: the subject is a part of a sentence or sentence or clause that performs the action of the verb or is described by the verb. 
    - Object name: the object is a part of a sentence or clause that is affected by the action of the verb or is the recipient of the action.
    - Location
    Format your response as a JSON object with "date" , "subject" , "object" and "location" as the keys.
    Subject and Object must be entity name.
    If the information isn't present, use "unknown" as the value.
    Make your response as short as possible.