p5.js Begginer - RNG not working

So i just wanted to make a generator that generates a random value every 10 seconds. And instead it generates a random valaue every frame after 10 seconds of waiting. Please correct me.

var imgs = [];
var a = 0

function randomizea() {
   a = int(random(5));
}

function setup() {
  createCanvas(1400, 850);

//  for (var i=0; i<5; i++) {
//    imgs[i] = loadImage("data/img"+i+".png");
//  }
}
function draw() {
  background(150, 100, 150);
  setInterval(randomizea, 1000);
//  image(imgs[a], 0, 0);
text(a, 0, 50);
}