在perl中正则表达式中的OR条件

I am trying to write a script which performs an OR function through regular expressions in Perl. I have written a code in which if string contains 'D' or 'E' followed by 'P' it should print "D or E followed by P" otherwise "D or E not followed by P". Suppose if I give $s = 'ABCDEABCDEPABCDEAB' it should print the else condition but I think my if statement is not working properly. Please help.I am trying to write a script which performs an