var f,g:text;
    max,k,l,n,m,i,j,t:longint;
    a:array[1..16,1..16]of longint;
    q,w:array[1..16,1..16]of longint;
begin
assign(f,'flip.in');reset(f);
assign(g,'flip.out');rewrite(g);
readln(f,n,m);
for i:=1 to n do
    begin
         for j:=1 to m do
             read(f,a[i,j]);
    readln(f);
    end;
    t:=1;
    for k:=1 to n do
    for l:=1 to m do
    begin
    for i:=1 to n do
        for j:=1 to m do
            w[i,j]:=a[i,j];
    for j:=1 to m do
        w[k,j]:=w[k,j]*-1;
    for i:=1 to n do
        w[i,l]:=w[i,l]*-1;

    for i:=1 to n do
        for j:=1 to m do
            q[k,l]:=q[k,l]+w[i,j];
    end;
    max:=0;
for i:=1 to n do
    for j:=1 to m do
        if q[i,j]>max then max:=q[i,j];
writeln(g,max);
close(g);
end.