var f,g:text;
    l1,l,c,c1:array[1..16] of longint;
    v:array[1..16,1..16] of longint;
    n,m,i,x,xx,j,s,max,q:longint;
begin
assign(f,'flip.in');reset(f);
assign(g,'flip.out');rewrite(g);
read(f,n,m);
for i:=1 to n do
    for j:=1 to m do begin
        read(f,v[i,j]);
        l[i]:=l[i]+v[i,j];
        c[j]:=c[j]+v[i,j];
        end;
max:=0;
for i:=1 to n do
    max:=max+l[i];
for i:=1 to m do
    max:=max+c[i];
max:=max div 2;
for x:=1 to 1 shl (m+n-1) do begin
    xx:=x;
    s:=0;
    for i:=1 to m+n do begin
        if xx mod 2=1 then begin
                           if i<=n then begin
                              l1[i]:=l1[i]*-1;
                              for j:=1 to m do
                                  inc(c1[j],2*v[i,j]);
                              end;
                           if i>n then begin
                              c1[i]:=c1[i]*-1;
                              for j:=1 to m do
                                  inc(l1[j],2*v[j,i]);
                              end;
                           end;
        xx:=xx div 2;
        end;
    for j:=1 to n do begin
        s:=s+l1[j];
        l1[j]:=l[j];
        end;
    for j:=1 to m do begin
        s:=s+c1[j];
        c1[j]:=c[j];
        end;
    s:=s div 2;
    if s>max then max:=s;
    end;
writeln(g,max);
close(f);
close(g);
end.