1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
#include <iostream>
#include <math.h>

int N, K;
int BEST = 2020;


int main() {
    std::ios::sync_with_stdio(false);

    std::cin >> N >> K;

    for (int row = 1; row <= N; row ++) {
        for (int col = 1; col <= row; col ++) {
            int year, bottles = col * (row + 1 - col);
            std::cin >> year;

            if (bottles <= K)
                BEST = std::min(BEST, year);
        }
    }

    std::cout << BEST << std::endl;
}