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  
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.  
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
assign(f,'flip.in');reset(f);
readln(f,n,m);
for i:=1 to n do
    begin
    for j:=1 to m do
//uses timer;
var phi:array[0..500000] of longword;   
i,j,k,n:longint;   
  
procedure smart; inline;   
var i,j,doi,jum:longint;   
rez:qword;   
k:longword;   
begin  
rez:=1; jum:=n div 2;   
for i:=2 to jum do phi[i]:=i-1;   
for i:=2 to jum do  
 begin  
 k:=phi[i]; doi:=2*i;   
 j:=3*i;   
 while (j<=jum) do  
  begin  
  dec(phi[j], k);   
  inc(j, doi);   
  end;   
 while (j<=n) do  
  begin  
  dec(rez, k); inc(j, doi);   
  end;   
 end;   
rez:=rez+int64(n-1)*n div 2-int64(jum-1)*jum div 2;   
writeln(2*rez-1);   
end;   
  
begin  
//start;   
assign(input,'fractii.in'); reset(input);   
assign(output,'fractii.out'); rewrite(output);   
readln(n);   
smart;   
//scurs;   
close(input); close(output);   
end.  
//uses timer;
var phi:array[0..500000] of longword;
i,j,k,n:longint;

procedure smart; inline;
var i,j,doi,jum:longint;
rez:qword;
k:longword;
begin
rez:=1; jum:=n div 2;
for i:=2 to jum do phi[i]:=i-1;
for i:=2 to jum do
 begin
 k:=phi[i]; doi:=2*i;
 j:=3*i;
 while (j<=jum) do
  begin
  dec(phi[j], k);
  inc(j, doi);
  end;
 while (j<=n) do
  begin
  dec(rez, k); inc(j, doi);
  end;
 end;
rez:=rez+int64(n-1)*n div 2-int64(jum-1)*jum div 2;
writeln(2*rez-1);
end;

begin
//start;
assign(input,'fractii.in'); reset(input);
assign(output,'fractii.out'); rewrite(output);
readln(n);
smart;
//scurs;
close(input); close(output);
end.