#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int n,m,s=0; cin>>n>>m; int a[n][m]; for(int i=0;i<=n-1;i++){ for(int j=0;j<=m-1;j++){ cin>>a[i][j]; } } for(int i=0;i<=n-1;i++){ for(int j=0;j<=m-1;j++){ if(i==n-1||j==m-1||i==0||j==0){ s+=a[i][j]; } } } cout<<s; return 0; }