my @R = ('Russ Ethan Jason Eric JAPH', 'JAPH vroom Ozymandias neshura Russ');

for (my $i = 0; $i != @R; $i++){
  while ($R[$i] =~ /Russ|JAPH/g){
    print "Found $& in string $i at: ", pos($R[$i]) - length $&, "\n";
  }
}