# include<iostream> # include<cstring> # include<cstdio> using namespace std; int main(){ int a[11][11],n,m,s=0; cin>>m>>n; for(int i=0;i<n;i++){ for(int j=0;j<m;j++){ cin>>a[i][j]; if(i==0||i==m-1||j==0||j==n-1){ s+=a[i][j]; } } }cout<<s; return 0; }