import java.util.Scanner;
public class Jin_bi_zui_da_zhi {
public static void main(String[] args) {
  Scanner sc=new Scanner(System.in);
  System.out.print("输入金币个数n：");
  int n=sc.nextInt();
  int a[]=new int[n+1];
  System.out.print("输入n个数：");
  for(int i=1;i<=n;++i)
      a[i]=sc.nextInt();
  sc.close();
  int max=hui(a,n);
  System.out.println("不相邻相加最大值是:"+max);
};
public static int hui(int[] a,int index){
    int n=a.length;
    int[] f=new int[n];
    f[0]=0;
    f[1]=a[1];
    for(int i=2;i<=index;++i)
    {
        int m=a[i]+f[i-2];
        int max=m>f[i-1]?m:f[i-1];
        f[i]=max;
    }
    return f[index];
};
}