unit sub MAIN( Int $N );

my $rt = now;
my $st = now;
my @i = 0,5,4,1,10,14,7; #flat "puzzle.input".IO.lines.first.split(",").map( *.Int );
my %n = @i.kv.reverse.map: { $^k => [$^v + 1, $^v + 1] };
my $l = @i[*-1];
my $t = @i.elems;

loop {
    $t++;
    $l = %n{ $l }[0] - %n{ $l }[1];
    %n{ $l }[1] = %n{ $l }[0] // $t;
    %n{ $l }[0] = $t;

    say "! $t { now - $st }" and $st = now
        if $t %% 1000000;

    last if $t == $N;
}

say $l;
say "RT { now - $rt }";