give me the count of all people who ascented a peak in wrangell-st . elias national park and preserve ?
SELECT DISTINCT COUNT attr_open var_uri attr_close where brack_open var_x dbo_locatedInArea dbr_Wrangell-St._Elias_National_Park_and_Preserve sep_dot var_x dbo_firstAscentPerson var_uri sep_dot var_uri a dbo_Person brack_close