#
# game of picking pairs of stones
# our strategy here is simply to search for the biggest chunk
# of stones and take the 2 of the middle
#

my ($rock-num, $player-name) = $*IN.lines;

exit say "aborted" unless $rock-num.defined and $player-name.defined;

my $is-computer = $player-name eq "computer";
my @rocks;

if $is-computer {
    say "computer takes 0,1";
    @rocks = 2..$rock-num-1;
} else {
    say "human to move: " ~ join "," ,^$rock-num;
    my ($a, $b) = $*IN.get.split(/\,/);
    @rocks = $b+1..$rock-num-1,^$a;
}

loop {
    my ($a, $b) = get-max @rocks;

    last unless $a.defined and $b.defined;
    
    $is-computer .= not;

    if $is-computer {
        say "computer takes $a,$b";
    } else {
        say "human to move: " ~ join ",", @rocks.grep({$_.defined});
        ($a, $b) = $*IN.get.split(/\,/);
    }
    for ^@rocks -> $i { undefine @rocks[$i] if $a|$b ~~ @rocks[$i] };
}
say ($is-computer ?? "computer" !! "human") ~ " wins";

sub get-max ( @array ) {
    my @numbers = gather for (
        max { $^a.comb.grep("S") > $^b.comb.grep("S") }, 
            ([~] "S" X @array.map({ $_ // "X" })).split(/SX/)
        ).match(/S(\d+)/,:g) -> $/ { take +$/[0] };
    return @numbers > 1 ?? @numbers[@numbers/2-1,@numbers/2] !! Any;
}