Regular Expression to match only the first block of text

Question

The text below has 3 blocks that start with /*+ and end with /*-. The regular expression (/[*][+]a[*]/)((?s).*)(/[*][-]a[*]/)\R matches all the text below. How can I match only the first block?

TEXT TEXT TEXT
TEXT TEXT TEXT

/*+a*/
--TEXT 1
--TEXT 1
/*-a*/

TEXT TEXT TEXT

/*+x*/
--TEXT 2
--TEXT 2
/*-x*/

TEXT TEXT TEXT
TEXT TEXT TEXT

/*+a*/
--TEXT 3
--TEXT 3
/*-a*/

TEXT TEXT TEXT
TEXT TEXT TEXT