m, n = map(int, input().split()) db = [] for j in range(m): sb = list(map(int, input().split())) db.append(sb) dsb = 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: dsb += db[i][j] print(dsb)