const 启动！

#include<bits/stdc++.h>
using namespace std;

const int N = 110;
int a[N][N];

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