include <bits/stdc++.h>

//#define int long long using namespace std; int a[1000][1000]; signed main(){

int n, m, sum=0;
cin>>n>>m;
for(int i=1;i<=n;i++){
	for(int j=1;j<=m;j++){
		cin>>a[i][j];
		if(i==1||i==n||j==1||j==m){
			sum+=a[i][j];
		}
	}
}
cout << sum;
return 0;

}