noi 9268 酒鬼

#include <bits/stdc++.h>
using namespace std;

int a[710];
int f[710][4];

int main()
{
    int n;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        scanf("%d",&a[i]);
    for(int i=1;i<=n;i++) {
        f[i][0] = f[i-1][3];
        int maxx = f[i][0];
        for(int j=1;j<=2;j++) {
            f[i][j] = f[i-1][j-1] + a[i];
            maxx = max(maxx,f[i][j]);
        }
        f[i][3] = maxx;
    }
    printf("%d\n",f[n][3]);

    return 0;
}