var n,nr,i:longint;
function cmmdc(i,j:longint):longint;
begin
if j=0 then cmmdc:=i else cmmdc:=cmmdc(j,i mod j);
end;
function prim(n:longint):longint;
var nr,i:longint;
begin
nr:=0;
for i:=2 to n-1 do
if cmmdc(n,i)=1 then nr:=nr+1;
prim:=nr+1;
end;
begin
 assign(input,'fractii.in');reset(input);
 read(n);
 assign(output,'fractii.out');rewrite(output);
 nr:=0;
 for i:=2 to n do
       nr:=nr+prim(i);
  write(1+2*nr);
end.