#include<bits/stdc++.h>
using namespace std;
int a[10000][10000],m,n ,f = 0;
int main()
{
    cin >> m >> n;    
	for(int i = 1;i <= n; i++)
        for(int j = 1;j <= m;j++) 
		{	
			cin >> a[i] [j];
			if((j == 1 || j == n) && (i != 1 && i != n) )
			{
			 	f += a[i] [j];		
			}
		}	
    for(int i=1;i<=m;i++)
		f += a[1] [i];
	for(int i=1;i<=m;i++)
		f += a[n] [i];
	cout << f;
	return 0;
}