include <bits/stdc++.h>

using namespace std; int a[1005][1005];

int main() {

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

}