>perl -wMstrict -le
"use constant MIN => 3;
 my $c = 'A';
 ;;
 my $s = 'uuAvvAAwwAAAxxAAAAyy';
 ;;
 printf qq{'$1' }
   while $s =~ m{ ([[:lower:]] (?:$c){${ \MIN },} [[:lower:]]) }xmsg;
"
'wAAAx' 'xAAAAy'