1619. House Robber

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define mp make_pair
#define pb push_back

/// HAHA
/// They have n <= (int)1e6 in statement
/// While in test they have n > 4e6
/// Are they clowns?

const int N = (int)6e6; /// >(int)1e6
const int INF = ((int)1e18);

int dp[N];

signed main()
{
    ios::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr);
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);

    int ans = 0;

    int n;
    cin >> n;

    int mx;

    for(int i = 4 ; i < n + 4 ; i ++)
    {
        cin >> dp[i];
        dp[i] += max(dp[i-2],dp[i-3]);
        ans = max(ans,dp[i]);
    }

    cout << ans;

    return 0;
}