#include <iostream>
using namespace std;
int main()
{
	int arr[100][100];
	int m,n;
	cin >> m >> n;
	if(m,n>=1&&m,n<=100)
	{
	     for (int i = 0; i < m; i++)
	    {
		    for (int k = 0; k < n;k++)
		    {
		    	cin >> arr[i][k] ;
		    }
    	}  
	
	
	    int sum = 0;
	    for (int i = 0; i < n; i++)
	    {
	    	sum += arr[0][i];
		    sum += arr[m - 1][i];
	    }
	    for (int i = 1; i < m - 1;i++)
	    {
	    	sum += arr[i][0];
	    	sum += arr[i][n - 1];
    	}
	    cout << sum << endl;
	}
	system("pause");
	return 0;
}