// get the slider value
    function getNumber(){
        let input = document.getElementById("userInput").value;
      return input
    }

    // triggered by the main button: set the number of exercises to "n"
    function myFunction() {
      let n = getNumber()

      // clear the list of any existing exercises
      document.getElementById("exercises").innerHTML = "";

      // define the array
      const all_exercises = [
        [" air squats ×40", "back squats ×20", "front squats ×20"], // alternatives group
        [" skip ×100"],
        [" burpees ×20"],
        [" row 500m", " row 250m"], // alternatives group
        [" pull-ups ×10", " ring pull-ups ×10", " pike ring pull-ups ×5", " finger board pull-ups ×10"], // alternatives group
        [" sit-ups ×35"],
        [" push-ups ×25", " ring push-ups ×10"], // alternatives group
        [" lunges ×30"],
        [" curls ×15"],
        [" ring rows ×12"],
        [" assisted ring dips ×10", " bench dips ×25"], // alternatives group
        [" power clean ×25", " power clean & jerk ×15", " power snatch ×10"], // alternatives group
        [" hanging leg raises ×20"],
        [" bench press ×10"],
        [" calf raises ×20"],
        [" plank 40s"],
        [" kettlebell swings ×20"],
        [" kettlebell push-press ×20"],
      ]

      // Set the max value of the slider (with id=userInput) to the # of elements in the array
      document.getElementById("userInput").setAttribute('max', all_exercises.length);

      // shuffle the full array
      function shuffleArray(array) {
        for (let i = array.length - 1; i > 0; i--) {
          const j = Math.floor(Math.random() * (i + 1));
          [array[i], array[j]] = [array[j], array[i]];
        }
      }

// pull out the first n values from the shuffled array and display as ordered list
shuffleArray(all_exercises);
    all_exercises.slice(0,n).forEach(e => {
      shuffleArray(e); // shuffle the nested array
        exercises.innerHTML =  exercises.innerHTML + '<li>' + e[0] + '</li>' ; // choose the first element using e[0]
    });
    }