# Adjacency matrix and chains and original board
class StonePairsGame {
    has @.board;
    has %.adj;
    has @.chains;

    method new ( $board_size ) {
        my @board = ^$board_size;
        my %adj;
        my @chains = [ @board ];
        for 0 ..^ @board.end -> $i {
            %adj{$i}{$i+1} = 1;
        }
        self.bless( *, :@board, :%adj, :@chains );
    }
}

my $N       = $*IN.get or say 'aborted' and exit;
my $player1 = $*IN.get or say 'aborted' and exit;

my $board = StonePairsGame.new($N);

if $N == 2|3 and $player1 eq 'computer' {
    say "computer takes 0,1\ncomputer wins";
}
elsif $N == 4 and $player1 eq 'computer' {
    say 'computer takes 0,1';
    $*IN.get eq '2,3' or busted();
    say "human to move: 2,3\nhuman wins";
}
elsif $N == 4 and $player1 eq 'human' {
    say 'human to move: 0,1,2,3';
    $*IN.get eq '1,2' or busted();
    say "computer takes 3,0\ncomputer wins";
}
else {
    busted();
}

sub busted () {
    die "
    .)ssenhsiloof tnatsnoc dna(
    .ycnetsisnoc hsiloof fo esnes a fo tuo dettimbus ylno si
    ,tset-esab eht etelpmoc ot staehc hcihw ,edoc sihT
    .emit fo tuo nar dna ,noitnetta eud sti 4P nevig ton dah I
    !em thguac uoY
    ".flip;
}