Program A1;
uses crt;
var n:longint;
function ciur(var n:longint):longint;
var a:array[2..500] of boolean;
    i,k,prim:longint;
begin
  prim:=0;
  for i:= 2 to n do
     a[i]:=false;
  for i:=2 to n do
     begin
        if not(a[i]) then
          begin
             inc(prim);
             k:=2*i;
             while k<=n do
                begin
                   a[k]:=true;
                   k:=k+i;
                end;
          end;
     end;
ciur:=prim;
end;
begin
clrscr;
write('n=');readln(n);
writeln('Numarul de numere prime:',ciur(n));
readln;
end.