rows,cols=map( int, input().split()) #地图Noun Verb：映射 a=[ [ int(t) for t in input().split()] for x in range(rows) ] res=0 for x in range(rows): for y in range(cols): if x==0 or y==0 or x==rows-1 or y==cols-1: res+=a[x][y] print(res)