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;
}