#include<iomanip> 
#include<cmath> 
#include<cstring> 
#include<cstdio> 
#include<algorithm> 
using namespace std;
const int N=1e2+8;
const int INF=0x3f3f3f3f;
int a[N][N],b[N][N],m,n,ans;
int main()
{
	cin>>n>>m;
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++)
			{
				cin>>a[i][j];
				if(i==n||i==1||j==1||j==m)
					ans+=a[i][j];	
			}
			cout<<ans;
	return 0;
}