s = 0 m,n = input().split() m,n = int(m),int(n) a = [] for i in range(m): t = input().split() a.append(t) 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)