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
#include <iostream>
#include <vector>
using namespace std;
using ULL = unsigned long long;
const int MAX_R = 2019;

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

	vector<vector<int>> v;
	int n, k, r;
	cin >> n >> k;

	for (int i = 1; i <= n; i++) {
		v.push_back(vector<int>());
		for (int j = 1; j <= i; j++) {
			cin >> r;
			v[i-1].push_back(r);
		}
	}

	int minr = MAX_R;
	for (int i = 1; i <= n; i++) {
		if (i > k) break;
		for (int j = 1; j <= i; j++) {
			if (j * (i - j + 1) > k) break;

			minr = min(minr, min(v[i-1][j-1], v[i-1][i-j]));
		}
	}

	cout << minr << '\n';

	return 0;
}