1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
#include <bits/stdc++.h>
#include <math.h>
#include <chrono>
using namespace std;
#pragma GCC optimize("-O3")
#define endl "\n"
#define mp make_pair
#define st first
#define nd second
#define pii pair<int, int>
#define pb push_back
#define _upgrade ios_base::sync_with_stdio(0), cout.setf(ios::fixed), cout.precision(10) //cin.tie(0); cout.tie(0);
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define FWD(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define fwd(i, a, b) for (int i = (a); i < (b); ++i)
#define all(c) (c).begin(), (c).end()
#define what(x) cerr << #x << " is " << x << endl;

const int MAXN = 2e3 + 99;

int dp[MAXN][MAXN];
int up[MAXN][MAXN];

int n, k;

void pre()
{
    cin >> n >> k;
    //cerr << n << endl;

    int odp = 1e6;
    for (int i = n; i > 0; i--)
        for (int j = 1; j + i <= n + 1; j++)
        {
            up[i][j] = up[i + 1][j] + 1;
            dp[i][j] = dp[i + 1][j - 1] + up[i][j];
            int a;
            cin >> a;
            if (dp[i][j] <= k)
                odp = min(odp, a);
            //cerr << a << " " << dp[i][j] << " " << up[i][j] << endl;
        }
    cout << odp << endl;
}
main()
{
    _upgrade;
    pre();
}