program fractii;
var i,j,n,s:longint;
    g,f:text;
function cmmdc(i,j:longint):longint;
var x,y,r:longint;
begin
x:=i;
y:=j;
r:=x mod y;
while r>0 do
begin
x:=y;
y:=r;
r:=x mod y;
end;
cmmdc:=y;
end;
begin
assign(f,'fractii.in');
assign(g,'fractii.out');
reset(f);
rewrite(g);
readln(f,n);
for i:=1 to n do
for j:=i to n do
if cmmdc(i,j)=1 then
s:=s+1;
s:=s*2-1;
writeln(g,s);
close(f);
close(g);
end.
{program fractii;
var i,n,s,a,b:longint;
    g,f:text;
begin
assign(f,'fractii.in');
assign(g,'fractii.out');
reset(f);
rewrite(g);
readln(n);
s:=n;
for i:=2 to n-1 do
begin
b:=n;
a:=i;
while a<>b do
if a>b then
a:=a-b
else
b:=b-a;
s:=s+n-a;
end;
s:=s+n-1;
for i:=2 to trunc(sqrt(n)) do
if n mod i=0 then
s:=s-1;
writeln(s);
close(f);
close(g);
end. }