Find ant build out file from another buld file

Find ant build out file from another buld file

I build several projects by using this code:
<ant antfile="${std.path}/src/@{project}/build.xml"
target="${build.type}"
inheritAll="false"/>
before it, I create their build.xml files by using this code:
<exec dir="${sdk.dir}/tools" executable="android.bat">
<arg line="update"/>
<arg line="project"/>
<arg line="--path"/>
<arg line="${std.path}/src/@{project}"/>
</exec>
Now i need to find and copy .apk files. But i found some problem there,
for project App1 (example) apk file named Activity1-release.apk, but for
App2 project it's named App2-release.apk . How i can find this apk files?