function prim(x,y:longint):boolean;
         var i,aux:longint;
             f1:boolean;
         begin
              if y>x then begin
                               aux:=x;
                               x:=y;
                               y:=aux;
                           end;
              f1:=true;
              for i:=2 to y do
                       if (y mod i=0) and (x mod i=0) then f1:=false;
              prim:=f1
         end;{verificare numere prime}
var f,g:text;
    a,n,i,j:longint;
begin
     assign(f,'fractii.in');
     reset(f);
     assign(g,'fractii.out');
     rewrite(g);
     read(f,n);
     close(f);
     a:=0;
     for i:=1 to n do
         for j:=1 to i div 2 do
             if prim(i,j)=true then a:=a+1;
     write(g,a);
     close(g);
end.