Given the root of a binary tree root where each node has a value, return the level of the tree that has the minimum sum of values among all the levels (in case of a tie, return the lowest level).

Note that the root of the tree is at level 1 and the level of any other node is its distance from the root + 1.

 

Example 1:

Example 2:

Example 3:

 

Constraints:

• The number of nodes in the tree is in the range [1, 105].
• 1 <= Node.val <= 109