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.