Problem 3

Write a program that takes an integer N and an array of N integers as input. Your program should output the maximum perimeter of a triangle that can be made if we take exactly 3 integers from the inputted array and form a triangle. Your program should output -1 if it's not possible to create a triangle with the inputted values.

Note: The integer N will be given in the first line and the array of N integers will be given in the second line (each integer separated by a single space).

Example:

Case 1:

For the input provided as follows:

3
1 2 3

Output of the program will be:

-1

Description of the output:

It's not possible to create a triangle with values 1, 2 and 3.

Case 2:

For the input provided as follows:

4
1 1 1 1

Output of the program will be:

3

Description of the output:

The maximum perimeter we can get is by taking 1, 1 and 1 and create a triangle that gives 3 as perimeter.