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.