import java.util.*;
 
class Ideone{
 
	public static void main(String[] args){
		int[] a = { 3, 2, 2, 3, 1, 2 };
 
		int maxSum = maxSum(a, 0, a.length-1);
		System.out.println("Max sum => "+ maxSum);
	}
 
 
	private static int maxSum(int[] a, int start, int end){
		if(start < 0 || end > a.length-1 || start > end) return 0;
 
		int sum1 = a[start] + min(maxSum(a, start+1, end-1), maxSum(a, start+2, end));
		int sum2 = a[end] + min(maxSum(a, start+1, end-1), maxSum(a, start, end-2));
 
		return sum1 > sum2 ? sum1 : sum2;
	}
 
	private static int min(int a, int b){
		return a<b ? a :b;
	}
}