var f,g:text;   
    smax:longint;   
    a:array [1..16,1..16] of longint;    
    sol:array [1..16] of -1..1;   
    n,m,i,j:longint;   
  
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);   
assign(g,'flip.out');rewrite(g);   
readln(f,n,m);   
for i:=1 to n do   
    for j:=1 to m do   
        read (f,a[i,j]);   
smax:=0;   
back(1);   
write(g,smax);   
close(g);   
end.