var n,m,i,j,sum1,sum,suma:longint;
    v:array[1..16,1..16] of integer;
    a:array[1..18] of integer;
f,g:text;
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,v[i,j]);
     end;
     readln(f);
end;
sum:=-maxlongint;
a[1]:=-1;
repeat
a[1]:=a[1]+1;
i:=1;
while a[i]=2 do begin
a[i]:=0;
i:=i+1;
a[i]:=a[i]+1;
end;
suma:=0;
if a[n+1]<>1 then
             for i:=1 to m do begin
                sum1:=0;
                for j:=1 to n do
                if a[j]=1 then sum1:=sum1-v[j,i]
                          else sum1:=sum1+v[j,i];
         if sum1>0 then suma:=suma+sum1
                   else suma:=suma-sum1;
                  end;
if suma>sum then sum:=suma;
until a[n+1]=1;
write(g,sum);
close(f);
close(g);
end.