var n,i,j,nr,total:int64;

    f,g:text;


function cmmdc (a,b:int64) : int64;
var aux:int64;
begin
        while a<>b do
        begin
                aux:=a;
                a:=b;
                b:=abs(aux-b);
        end;

        cmmdc:=a;
end;



begin
assign(f,'fractii.in');reset(F);
assign(g,'fractii.out');rewrite(g);
readln(f,n);

i:=1; j:=1;

while i<=n do
begin
        while (j<=n)and(i<=n) do if cmmdc(i,j)=1 then
        begin
                inc(total);
                inc(j);
        end
                                                 else
                inc(j);



        inc(i); j:=1;
end;

writeln(g,total);

close(g);
end.