#include <bits/stdc++.h>
using namespace std;

const int MAXN = 1010;
const int dx[] = {-1, 1, 0, 0};
const int dy[] = {0, 0, -1, 1};

int n, m;
int p[MAXN][MAXN];
bool visited[MAXN][MAXN];

bool check(int d) {
    memset(visited, false, sizeof(visited));
    queue<pair<int, int>> q;
    for (int j = 1; j <= m; j++) {
        if (p[1][j] <= d) {
            q.push({1, j});
            visited[1][j] = true;
        }
    }


    while (!q.empty()) {
        auto t = q.front();
        q.pop();
        int x = t.first,y = t.second;
        for (int i = 0; i < 4; i++) {
            int nx = x + dx[i];
            int ny = y + dy[i];
            if (nx >= 1 && nx <= n && ny >= 1 && ny <= m && !visited[nx][ny] && p[nx][ny] <= d) {
                visited[nx][ny] = true;
                q.push({nx, ny});
            }
        }
    }

    for (int j = 1; j <= m; j++) {
        if (!visited[n][j]) {
            return false;
        }
    }
    return true;
}

int main() {
    cin >> n >> m;
    int maxP = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> p[i][j];
            maxP = max(maxP, p[i][j]);
        }
    }


    int left = 0, right = maxP;
    int ans = maxP;
    while (left <= right) {
        int mid = (left + right) / 2;
        if (check(mid)) {
            ans = mid; 
            right = mid - 1; 
        } else {
            left = mid + 1;
        }
    }

    cout << ans << endl;
    return 0;
}

#include <bits/stdc++.h>

using namespace std;

const int N = 1010;
int dx[4] = {0,0,-1,1},dy[4] = {1,-1,0,0};
int n,m;
bitset<N> vis[N];
int grids[N][N];
int max1 = 0,ans = 0;

bool f(int x,int y)
{
  return (x>=1&&x<=n&&y<=m&&y>=1);
}



bool dfs(int x,int y ,int s)
{
  if(x == n)return true;
  vis[x][y] = true;
    for(int j = 0;j<4;j++)
    {
      int nx = x+dx[j],ny = y+dy[j];
      if(f(nx,ny)&&!vis[nx][ny]&&grids[nx][ny]<=s)
      {
        if(dfs(nx,ny,s))
        return true;
      }
    }
    return false;
  }

bool check(int s)
{
  memset(vis, false, sizeof(vis)); 
    for (int j = 1; j <= m; j++) {
        if (grids[1][j] <= s && dfs(1, j, s)) {
            return true; 
        }
    }
    return false; 
}
int main()
{
  
  cin>>n>>m;
  for(int i = 1;i<=n;i++)
  for(int j = 1;j<=m;j++)
  {
    cin>>grids[i][j];
    max1 = max(max1,grids[i][j]);
  }

  int l = 0,r = max1;
  while(l<=r)
  {
    int mid = (l+r)/2;
    if(check(mid))
    {
      ans = mid;
      r = mid-1;
    }else  {
      l = mid+1;
    }
  }
  cout << ans << endl;
  return 0;
}