var i,j,ii,jj,c,n:longint; f:text;
begin
assign(f,'fractii.in');reset(f);read(f,n);close(f);
c:=0;
for i:=1 to n do
    for j:=1 to n div 2 do begin
        ii:=i; jj:=j;
        while ii<>jj do
              if ii>jj then ii:=ii-jj
                       else jj:=jj-ii;
        if ii=1 then c:=c+2;     end;
assign(f,'fractii.out');rewrite(f);write(f,c);close(f); end.