Vardges,
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
body{
display:flex;
flex-wrap:wrap;
justify-content: center;
width: 50%;
}
div{
width: 100px;
height: 100px;
border:1px solid;
font-size: 24px
}
</style>
</head>
<body>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
</body>
<script>
var elem=document.querySelectorAll('div');
for (var i=0;i<elem.length;i++){
elem[i].addEventListener('click',F)
}
var a=[];
function F(){
if(this.innerHTML!=""){
return false
}
var x=parseInt(Math.random(1)*9);
this.innerHTML = x;
a.unshift(this);
if(a.length == 3) {
var t = a[2].innerHTML;
a[2].innerHTML = a[1].innerHTML;
a[1].innerHTML = t;
a.length = 2;
}
console.log(a)
}
</script>
</html>