#include<iostream>
#include<algorithm>
using namespace std;
int a[110][110];
int main()
{
	int n, m,sum=0;
	cin >> n >> m;
	for (int i = 1; i <= m; i++) {
		for (int j = 1; j <= n; j++) {
			cin >> a[i][j];
		}
	}
	for (int i = 1; i <= n; i++)
	{
		sum += a[1][i];
		sum += a[m][i];
	}
	for (int j = 1; j <= m; j++)
	{
		sum += a[j][1];
		sum += a[j][n];
	}
	printf("%d", sum - a[1][1] - a[m][n] - a[1][n] - a[m][1]);
	return 0;
}