Input:
<thead>
abc   <ex>bcd</ex>   <lp>def</lp>
abc   <ex>bcd</ex>   def
abc   bcd   def
</thead>
OUTPUT:
<thead>
<row><col>abc</col><col><ex>bcd</ex></col><col><lp>def</lp></col></row>
<row><col>abc</col><col><ex>bcd</ex></col><col>def</col></row>
<row><col>abc</col><col>bcd</col><col>def</col></row>
</thead>