Hello,

I am getting a runtime error on my Go solution which I don't understand. Here is the function:

```
func addTwoNumbers(l1 *ListNode, l2 *ListNode) *ListNode {
res := &ListNode{}
curr := res
l1 = &ListNode{Next: l1}
l2 = &ListNode{Next: l2}
for *l1.Next != (ListNode{}) {
l1 = l1.Next
l2 = l2.Next
sum := curr.Val + l1.Val + l2.Val
mod := sum % 10
curr.Val = mod
curr.Next = &ListNode{}
curr = curr.Next
curr.Val = (sum - mod) / 10
}
return res
}
```

The thing is that that leetcode doesn't give me the error, it just tells me that the result is empty. Here is the working code on the Go playground. Can anyone see the error, what have I done wrong?

Thank you!