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
#include <cstdint>
#include <iostream>

int main() {
  int64_t n = 0;
  int64_t k = 0;

  std::cin >> n;
  std::cin >> k;

  int64_t min = 2020;

  for (int64_t i = 1; i < n + 1; ++i) {
    if (i > k) {
      break;
    }

    for (int64_t j = 1; j < i + 1; ++j) {
      int64_t year = 0;
      std::cin >> year;

      int64_t dist = j * (i + 1 - j);

      if (dist <= k) {
        min = std::min(min, year);
      }
    }
  }

  std::cout << min << std::endl;
  return 0;
}