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;
}
