UVA - 12484 - Cards

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
  
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuffer sb = new StringBuffer("");
        String m="";
        while((m=br.readLine())!=null){
            int n=Integer.parseInt(m);
            long[]arr=new long[n];
            String[]str=br.readLine().split(" ");
            for(int i=0;i<n;i++){
                arr[i]=Integer.parseInt(str[i]);
            }
            long[][]sum=new long[2][n];
            boolean flag=true;
            for(int i=1;i<n;i++){
                if(flag){
                   for(int j=0;j<n-i;j++){
                       sum[1][j]=Math.max(sum[0][j] + arr[i + j], arr[j] + sum[0][j + 1]);
                   }
                   flag=false;
                }else{
                    for(int j=0;j<n-i;j++){
                        sum[0][j]=Math.min(sum[1][j], sum[1][j + 1]);
                    }
                  flag=true;
                }
            }
            sb.append(sum[1][0]).append("\n");
        }
        System.out.print(sb);
    }
}