sub decomp {
    @_ = split / /, shift;
    return [ map { join " ", (shift, shift, $_[0]) } (1..@_/2) ];
}

##</code><code>##

sub decomp {
    my $n = 2; # for n+1-uples
    @_ = split / /, shift;
    return [ map { $_*=$n; "@_[$_..$_+$n]" } 0..@_/$n-1 ];
}