var f,g:text; 
a:array[1..16,1..16] of longint; 
s,ss,smax,hhh:longint; 
k,i,j,n,m:byte; 
x:array[0..16] of byte; 
begin
assign(f,'flip.in');reset(f); 
assign(g,'flip.out');rewrite(g); 
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; 
k:=1; 
while k>0 do
begin
if x[k]<2 then x[k]:=x[k]+1; 
if k=n then begin
ss:=0; 
for j:=1 to m do begin
s:=0; 
for i:=1 to n do
begin
if x[i]=2 then s:=s-a[i,j] 
else s:=s+a[i,j]; 
end; 
if s<0 then ss:=ss-s 
else ss:=ss+s; 
end; 
if ss>smax then smax:=ss; 
while x[k]=2 do
begin
k:=k-1; 
end; 
end
else begin
k:=k+1; 
x[k]:=0; 
end
end; 
write(g,smax); 
close(f); 
close(g); 
end.