m,n=input().split() m,n=int(m),int(n) a=[] for i in range(m): tmp=input().split() a.append(tmp) s=0 for i in range(m): for j in range(n): if i==0 or i==m-1 or j==0 or j==n-1: s=s+int(a[i][j]) print(s)