#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;

const int MAX_N = 1000;
//vector<vector<int>> graph(MAX_N, vector<int>());
int trees[MAX_N][MAX_N];
int visited[MAX_N][MAX_N];
int arr[MAX_N*MAX_N];
int n,d;

void clearVisited()
{
	for(int i = 0; i < n; ++i)
	{
		for(int j = 0; j < n; ++j)
		{
			visited[i][j] = 0;
		}
	}
}

bool canBuild(int oldest)
{
	queue<pair<int,int>> Q;
	queue<int> Q2;

	for(int i = 0; i < n; ++i)
	{
		for(int j = 0; j < n; ++j)
		{
			if(!visited[i][j])
			{
				visited[i][j] = 1;
				Q.push(pair<int,int>(i,j));
				Q2.push(1);

				while(!Q.empty())
				{
					pair<int,int> coords = Q.front();
					Q.pop();
					int volume = Q2.front();
					Q2.pop();

					if(volume >= d)
					{
						clearVisited();
						return 1;
					}

					if(coords.first > 0)
					{
						if(trees[coords.first-1][coords.second] <= oldest && !visited[coords.first-1][coords.second])
						{
							visited[coords.first-1][coords.second] = 1;
							Q.push(pair<int,int>(coords.first-1, coords.second));
							Q2.push(volume+1);
						}
					}

					if(coords.first < n-1)
					{
						if(trees[coords.first+1][coords.second] <= oldest && !visited[coords.first+1][coords.second])
						{
							visited[coords.first+1][coords.second] = 1;
							Q.push(pair<int,int>(coords.first+1, coords.second));
							Q2.push(volume+1);
						}
					}

					if(coords.second > 0)
					{
						if(trees[coords.first][coords.second-1] <= oldest && !visited[coords.first][coords.second-1])
						{
							visited[coords.first][coords.second-1] = 1;
							Q.push(pair<int,int>(coords.first, coords.second-1));
							Q2.push(volume+1);
						}
					}

					if(coords.second < n-1)
					{
						if(trees[coords.first][coords.second+1] <= oldest && !visited[coords.first][coords.second-1])
						{
							visited[coords.first][coords.second+1] = 1;
							Q.push(pair<int,int>(coords.first, coords.second+1));
							Q2.push(volume+1);
						}
					}
				}
			}
		}
	}

	clearVisited();
	return 0;
}

int main() {
	int w;
	cin >> n >> d;
	for(int i = 0; i < n; ++i)
	{
		for(int j = 0; j < n; ++j)
		{
			cin >> w;
			trees[i][j] = w;
			arr[i*n+j] = w;
		}
	}

	sort(arr, arr + n*n);

	int l = 0, r = n*n-1, mid;
	int res;

	while(l <= r)
	{
		mid = (l+r)/2;

		if(canBuild(mid))
		{
			r = mid - 1;
			res = mid;
		}
		else
		{
			l = mid + 1;
		}
	}

	cout << mid;

	return 0;
}