rewrite rule with 3 parameters

How do i use rewrite rule with 3 parameter开发者_开发百科es? like:

RewriteRule example/$/$/$ example.php?x=$1&y=$2&z=$3

thank you

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Ok ;

i found the answer :

RewriteRule ex/([^/]+)/([^/]+)/([^/]+) ex.php?x=$1&y=$2&z=$3 [L]
RewriteRule ex/([^/]+)/([^/]+) ex.php?x=$1&y=$2 [L]
RewriteRule ex/([^/]+) ex.php?x=$1 [L]

thanks to Tim Cooper for editing help.