templates male
  when <=0> do 0 !
  otherwise def n: $;
     $n - 1 -> male -> female -> $n - $ !
end male

templates female
  when <=0> do 1 !
  otherwise def n: $;
     $n - 1 -> female -> male -> $n - $ !
end female

0..10 -> 'M$;: $->male; F$;: $->female;
' -> !OUT::write