row,col=input().split() row=int(row) col=int(col) a=[] for x in range(row): t=input().split() t=[int(x) for x in t] a.append(t) s=0 for i in range(row): for j in range(col): if i==0 or i==row-1 or j==0 or j==col-1: s=s+a[i][j] print(s)