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

int main() {
    int n, m;
    cin >> n >> m;
    int mat[n][m];
    
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            cin >> mat[i][j];
        }
    }
    vector<int> v;
    
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            int najmal_element = 2000000000;
            if(i + 1 < n) { // dolniot sosed
                najmal_element = min(najmal_element, mat[i + 1][j]);
            }
            
            if(i - 1 >= 0) { // gorniot sosed
                najmal_element = min(najmal_element, mat[i - 1][j]);
            }
            
            if(j + 1 < m) { // desniot sosed
                najmal_element = min(najmal_element, mat[i][j + 1]);
            }
            
            if(j - 1 >= 0) { // leviot sosed
                najmal_element = min(najmal_element, mat[i][j - 1]);
            }
            if(najmal_element > mat[i][j]) {
                v.push_back(najmal_element - mat[i][j]);
            }
        }
    }
    if(v.size() == 0) {
        cout << -1 << endl;
    }
    else {
        sort(v.begin(), v.end());
        for(int i = v.size() - 1; i >= 0; i--) {
            cout << v[i] << " ";
        }
    }
    return 0;
}