So i have two sorted lists with deliverable's and I want to Merge them. I never did this operation before and i can not really make it work. You can see method below that i wrote. I can not figure out while statement because it fires exception all the time. I dont know what to do...

```
public void MergeLists(List<Deliverable> a, List<Deliverable> b)
{
    int index1 = 0;
    int index2 = 0;

    while (a.Count() >= index1 || b.Count() >= index2)
    {
        if (a[index1].ID> b[index2].ID)
        {
            FinalDeliverables.Add(a[index1]);
            index1++;
        }
        else if (a[index1].ID < b[index2].ID)
        {
            FinalDeliverables.Add(a[index2]);
            index2++;
        }
        else if (a[index1].ID == b[index2].ID)
        {
            FinalDeliverables.Add(a[index1]);
            FinalDeliverables.Add(a[index2]);
            index1++;
            index2++;
        }
    }
}

```