for ($k=0; $k<=$#Mdevices; $k++)
  {
    print $Mdevices[$k][0],"\n";
  }

for my $device (@Mdevices) {
    print $device->[0], "\n";
}

##</code><code>##

print $_->[0], "\n" for @Mdevices;

##</code><code>##

for (1 ..5) {
    push (@Cdevices, "UnitId$_", $_);
    push (@Mdevices, \@Cdevices);
}

print $_->[0], "\n" for @Mdevices;

##</code><code>##

UnitId1
UnitId1
UnitId1
UnitId1
UnitId1