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

ll a[200010];
int n;

ll solve(int i)
{
    if(i==n) return a[n];
    return max(solve(i+1),a[i]-solve(i+1));
}

int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%lld",&a[i]);
        a[i]+=a[i-1];
    }
    printf("%lld\n",solve(2));
}