Question
First Repeated Element

Pranav is playing a game with a list of numbers. He wants to find the first number that appears more than once in the list. If no number repeats, he will consider the list “unique” and print -1.

Can you help Pranav find the number he is looking for? 

Input
The only line contains space-separated integers representing the list.
Output
  • An integer representing the first repeated element in the list.
  • If no element repeats, return -1.
Example
Example 1
Input:
2 5 1 2 3 5

Output:
2

Explanation:
While reading the numbers, Pranav encounters 2 again first, so the answer is 2.


Example 2
Input:
1 2 3 4

Output:
-1

Explanation:
All numbers are unique, so Pranav prints -1.

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