var a:array[1..16,1..16]of longint;f,g:text;
    b,l:array[1..17]of longint;n,m,max,s,j,i:longint;
begin
assign(f,'flip.in');reset(f);assign(g,'flip.out');rewrite(g);read(f,n,m);
for i:=1 to n do begin
for j:=1 to m do begin
read(f,a[i,j]);l[i]:=l[i]+a[i,j];end;
max:=max+l[i];end;
while b[m+1]=0 do begin j:=1;
while b[j]=1 do begin b[j]:=0;
for i:=1 to n do l[i]:=l[i]+2*a[i,j];j:=j+1;end;b[j]:=1;
for i:=1 to n do l[i]:=l[i]-2*a[i,j]; s:=0;
for i:=1 to n do s:=s+abs(l[i]);
if s>max then max:=s;end;write(g,max);close(f);close(g);end.