$(function () {
   var numbers = $('td'),
       num_selected = 0,
       nextButton = $('.otree-btn-next'),
       numCorrect = $('input[name^=grit_num_correct]');

   numbers.on('click touch', function () {
       num_selected++;
       if (!$(this).hasClass('correct')){
           $(this).removeClass('not-done').addClass('selected');
       }
       var sum = 0,
           selected = $('.selected');
       if (num_selected === 2) {
           selected.each(function(){
               sum += parseInt($(this).text());
           });
           if (sum === 100) {
               selected.addClass('correct').removeClass('selected');
           } else {
               setTimeout(function () {
               selected.removeClass('selected').addClass('not-done')
               }, 400)
           }
           num_selected = 0;
       }
       numCorrect.val($('.correct').length/2);

       if (numCorrect.val() === '3'){
           $('#form').submit()
       }
   })
});