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
#include <iostream> 
#include <limits.h> 
#include <string.h> 
#include <queue> 
#include <iomanip>
#include <cmath>
#include <set>
#include <map>
#include <vector>
#include <algorithm>
#include <iomanip>
#include <unordered_map>

using namespace std; 
  
typedef long long LL;

const int MOD = 1e9+7;
int t[2007][2007];
int res = 3000;

int solve(int i, int j)
{
    int left = max(j - 2, 0);
    int right = max((i - j + 1 - 2), 0);
    i --;
    //cout << i << " " << j << " " << left  << " " << right << " " << << "\n";
    return ((i * (i + 1)) / 2) - (left * (left + 1) / 2) - (right * (right + 1) / 2) + 1;
}

int main() 
{ 
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    LL n, k; cin >> n >> k;

    for(int i = 1; i <= n; i ++)
    {
        for(int j = 1; j <= i; j ++)
        {
            cin >> t[i][j];
            if(solve(i, j) <= k) res = min(res, t[i][j]);
        }
    }
    cout << res << "\n";
    return 0; 
}