tren

#include <iostream>
#include <fstream>
using namespace std;

int s[1001][1001], suma[1001], n, v[1001], k = 3, m = 2;

int main()
{
    freopen("test.in", "r", stdin);
    freopen("test.out", "w", stdout);
    cin >> n;
    for(int i = 1; i <= n; i++)
        cin >> v[i], suma[i] = suma[i-1] + v[i];
    for(int i = 1; i <= k; i++)
    {
        for(int j = 1; j <= n; j++)
        {
            s[i][j] = max(s[i][j-1], suma[j] - suma[j-m] + s[i-1][j-m]);
        }
    }
    for(int i = 1; i <= n; i++)
    {
        for(int j = 1; j <= n; j++)
        cout << s[i][j] << ' ';
        cout << '\n';
    }
}