var f,g:text;
    s,i,j,n,m,max,t:longint;
    a:array[1..16,1..16]of longint;
    b,q:array[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;
for i:=1 to n do
    for j:=1 to m do
    if a[i,j]<=0 then b[i]:=b[i]+1;
t:=1;
for j:=1 to m do
for i:=1 to n do
    if a[i,j]<=0 then q[j]:=q[j]+1;
for i:=1 to n do
    if max<b[i]then begin
                    t:=i;
                    max:=b[i];
                    end;
for i:=1 to m do
    a[t,i]:=a[t,i]*-1;
for i:=1 to m do
    if max<q[i] then begin
                     t:=i;
                     max:=q[i];
                     end;
for i:=1 to n do
    a[i,t]:=a[i,t]*-1;
for i:=1 to n do
    for j:=1 to m do
        s:=s+a[i,j];
writeln(g,s);
close(g);
end.