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Here the ids are sequence for both the elements. I want to start the n
+ew id for 'a' element again from sec1.

...
  <a id="sec15">here the paragraph comes</a>
  <a id="sec16">here the paragraph comes</a>
</xml>

Required Output:
----------------
...
  <a id="sec11">here the paragraph comes</a>
  <a id="sec12">here the paragraph comes</a>
</xml>

use strict;
...

print $string;