include<bits/stdc++.h>

define ll long long

using namespace std;

ll n, a[1000005], pre[1000005];
map<ll, ll> minpre;
map<ll, ll> check;

int main()
{
cin >> n;
for(int i = 1; i <= n; i++)
{
cin >> a[i];
pre[i] = pre[i - 1] + a[i];
}
ll res = -1e18;
minpre[a[1]] = a[1];
check[a[1]] = true;
pre[1] = a[1];
for(int i = 2 ; i <= n; i++)
{
if(check[a[i]])
{
res = max(res, pre[i] - minpre[a[i]] + a[i]);
minpre[a[i]] = min(minpre[a[i]], pre[i]);
}
else
{
minpre[a[i]] = pre[i];
check[a[i]] = true;
}
}
cout << res;
}