eratosthenes_sieve

var
    a:array of boolean;
    i,j,n,m:longint;

Begin
  read(n,m);
  SetLength(a,m+1);
  for i:=2 to m do
    a[i]:=true;
  for i:=2 to trunc(sqrt(m)) do
    if a[i] then
       begin
         j:=sqr(i);
         while (j<=m) do
           begin
             a[j]:=false;
             inc(j,i);
           end;
       end;
end.