Oldest Pet

You get a Vec of pets, pets. Each pet is a pair: its name and its age, like ("Rex", 4).

Return the name of the oldest pet.

Several pets may share the oldest age. Then return the one that comes first in pets.

The starter code shows how your language holds a pair.

Example 1:

Input: pets = [("Rex", 4), ("Bella", 7), ("Max", 2)]
Output: "Bella"
Explanation: Bella is 7.
Rex and Max are younger.

Example 2:

Input: pets = [("Luna", 3), ("Coco", 9), ("Milo", 9)]
Output: "Coco"
Explanation: Coco and Milo are both 9.
Coco comes first in the list.

Example 3:

Input: pets = [("Kiki", 0)]
Output: "Kiki"
Explanation: Kiki is the only pet.

Constraints:

• pets has at least one pet.
• Every age is a whole number from 0 to 30.
• Each name is a capital letter followed by lowercase letters, like "Rex".