type ma=array [1..16,1..16] of longint;
     ta=array [1..16] of -1..1;   
var n,m,i,j:longint;   
    smax:longint;   
    a:ma;   
    sol:ta;   
    f:text;   
  
procedure evaluare;   
var i,j,s,sc:longint;   
begin  
s:=0;   
for i:=1 to m do  
    begin  
    sc:=a[1,i];   
    for j:=2 to n do  
        sc:=sc+sol[j]*a[j,i];   
    s:=s+abs(sc);   
    end;   
if smax<s then smax:=s;   
end;   
  
  
  
  
procedure back(p:integer);   
begin  
sol[p]:=1;   
if p=n then evaluare   
       else back(p+1);   
sol[p]:=-1;   
if p=n then evaluare   
       else back(p+1);   
end;   
  
  
  
begin
assign(f,'flip.in');reset(f);
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;
close(f);
smax:=0;
back(1);
assign(f,'flip.out');rewrite(f);
write(f,smax);
close(f);
end.