<form id="form_id-1">
<input id="dugi-56" value="10">
<input id="dugi-59" value="20">
</form>
<form id="form_id-2">
<input id="dugi-36" value="30">
<input id="dugi-49" value="40">
</form>
<form id="form_id-3">
<input id="dugi-6" value="50">
<input id="dugi-9" value="60">
</form>