sub blazar {
    @ARGV=@ARGV0;
    while (<>) {
        chomp;
        my $cnt;
        for my $p (@pre) {
            local $_ = $p . $_;
            if (-e) {
                # print;
                @pre[0..$cnt] = @pre[$cnt,0..$cnt-1] if $cnt;
                last;
            }
            $cnt++;
        }
    } 
}

sub aristotle {
    @ARGV=@ARGV0;
    while ( <> ) {
        chomp;
        for my $i ( 0 .. $#pre ) {
            local $_ = $pre[ $i ] . $_;
            next if not -e;
            # print;
            @pre[ 0 .. $i ] = @pre[ $i, 0 .. $i - 1 ] if $i;
            last;
        }
    }
}

sub naive {
    @ARGV=@ARGV0;
    while (<>) {
        chomp;
        for my $p (@pre) {
            local $_ = $p . $_;
            # print,
              last if -e;
        }
    } 
}