how to cast viewbag data in cshtml code example

Example 1: viewBag as a list

<td>@((ViewBag.data as ICollection<Person>).First().FirstName)</td>

Example 2: viewBag as a list

<ul>
    @foreach (var person in ViewBag.data)
    {
        <li>@person.FirstName</li>
    }
</ul>