Graphical mapping requirement

Hello Experts,

Can someone help me in this mapping :

Source XML :

<Root>

<Person>

   <PersonNumber>1234</PersonNumber>

- <Details>

  <Country>XXX</Name>

</Details>

</Person>

<Person>

   <PersonNumber>1234</PersonNumber>

- <Details>

  <Country>YYY</Country>

</Details>

</Person>

<Person>

   <PersonNumber>4321</PersonNumber>

- <Details>

  <Country>ZZZ</Country>

</Details>

</Person>

</Root>

Target XML :

<Root>

<Person>

   <PersonNumber>1234</PersonNumber>

- <Details>

  <Country>XXX</Name>

</Details>

- <Details>

  <Country>YYY</Country>

</Details>

</Person>

<Person>

   <PersonNumber>4321</PersonNumber>

- <Details>

  <Country>ZZZ</Country>

</Details>

</Person>

</Root>

The requirement is if the PersonNumber is same for any two occurence then we have to create only one Person node with the </Details> collated.

Rest all data will be passed as it is.

We have to do it only for a maximum of two occurences i.e. one person number can occur for a maximum of two times.

We want to achieve thsi using Graphical maaping.

Thanks

Gaurav