<input class="phone-mask" name="phone" type="text"><html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="jquery.mask.js"></script>
</head>
<body>
<input class="phone-mask" name="phone" type="text">
<script type="text/javascript">
$.jMaskGlobals = {translation: {
'n': {pattern: /\d/},
}
};
$('.phone-mask').mask('+380nn-nnn-nnnn').val('+380');
</script>
</body>
</html>