XML : How to avoid duplicates generated from XSLT

I have a for each loop on my xslt file, which will go and process multiple Conditions, If any of the conditions have a matching scenario than I want to exit out of the loop and give the first value(which has satisfied the condition) for my output.

Here is my xml file

       <Product>       <ContactDetails>       <addressdetail>       <Street>Stack</Street>       <HouseNumber>123</HouseNumber>       </addressdetail>       <addressdetail>       <Street>Stack</Street>       <HouseNumber>123456</HouseNumber>       </addressdetail>       <addressdetail>       <Street>Stack</Street>       <HouseNumber>456</HouseNumber>       </addressdetail>       </ContactDetails>       </Product>     

and in my XSL file i have some kinding like this

          <xsl:for-each select ="Product[ContactDetails= 'addressdetails']  ">              <xsl:if test="Street='Stack'" >              <p3:SC>abc</p3:SC>              </xsl:if>           </xsl:for-each>    

After the transformation, I am having three values on my output xml

            <p1:Product_Req>              <p2:ContactDetails_Req>                 <p3:ac>abc</p3:ac>              <p3:ac>abc</p3:ac>              <p3:ac>abc</p3:ac>              </p1:Product_Req>              </p2:ContactDetails_Req>      

But I dont need the repeting values on my output xml, I only need one value on my Xml node ac. I have tried using the identity transform but nothing seems like working, any help is highly appreciated