Card game

#include <iostream>
#include <cstdio>
#include <algorithm>

int main() {
    using namespace std;
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    int c1=0, c2=0, c3=-1<<30, c4=-1<<30, c5=-1<<30;
    while(n--) {
        int c0;
        cin >> c0;
        c0 = c0 + max({c3,c4,c5});
        c5 = c4;
        c4 = c3;
        c3 = c2;
        c2 = c1;
        c1 = c0;
    }
    cout << max({c2,c3,c4});
}
/*

                        0
    =====================
    1   0   0   0   0   1 -> c1 // c5
    0   1   0   0   0   1 -> c1 // c4
    0   0   1   0   0   1 -> c1 // c3

    0   1   0   0   0   0 -> c5
    0   0   1   0   0   0 -> c4
    x   0   0   1   0   0 -> c3
    x   x   0   0   1   0 -> c2


c1 xxxxx1
c2 xxxx10
c3 xxx100
c4 xx1000
c5 x10000


       *       *     *
     2 7 1 1 5 7 4 1 1
0    - 7 1 1 C E B 8 F<-
0    0 - 7 1 1 C E B 8
-    0 0 - 7 1 1 C E B
-    - 0 0 - 7 1 1 C E
-    - - 0 0 - 7 1 1 C

*/

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: UNKNOWN

Test 15

Verdict: UNKNOWN