program hio;  
  
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 {pp}  
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.