<input id="location" class="article" style="width:500px">
<input id="location" class="article gfd" style="width:500px">
<script>
var articles = document.getElementsByClassName('article');
//alert( articles.length ); // 2, найдёт оба элемента
// el = document.getElementById('location');
articles.value = document.getElementsByClassName("article").innerHTML = location;
</script>
el = document.getElementById('timer-counter');
el.value = document.getElementById("timer-counter").innerHTML = 5;
el = document.getElementById('timer-counter2');
el.value = document.getElementById("timer-counter2").innerHTML = 5;