function output = feeder (state, input)
%feed when 1 or time passes
if ((strcmp(input, '1')||strcmp(input,'time passes'))...
        && strcmp(state, 'hungry') ) 
        output='feed';
  %time passes when input is 1 and state != hungry  
  else if (strcmp(input, '1')) output='time passes';
    %all other inputs are fine, let them be
      else 
        output=input;
  end
end