var f,g:text;
    n,x,i,nr:longint;
function cmmdc(a,b:integer):integer;
begin
while a<>b do
begin
     if a>b then
        a:=a-b
     else
         B:=b-a;
end;
cmmdc:=a;
end;

begin
assign(f,'fractii.in');
assign(g,'fractii.out');
reset(f);
rewrite(g);
readln(f,n);
nr:=0;  x:=n;
while x>0 do
begin
     for I:=1 to n do
     begin
         if (i=1) or (x=1) then
            nr:=nr+1
         else
             if cmmdc(x,i)=1 then
                nr:=nr+1;
     end;
     x:=x-1;
end;
write(g,nr);
close(f);
close(g);
end.