<!doctype html>
<html>
<head>
<meta charset="utf-8">
<style>
input[type="button"]{
padding:20px;
border:none;
border-radius:50px;
font-size:2rem;
background: #0070bb;
color:#fff;
}
</style>
</head>
<body>
<input type="button" onclick="begen()" value="Tıkla Beğen">
<input type="button" id="sayi" value="0">
<script>
function begen(){
var sayi=document.getElementById("sayi");
sayi.value=Number(sayi.value)+1;
}
</script>
</body>
</html>