program totient;
    loop for n in [1..1000000] do
        tot := totient(n);
        if tot = n-1 then prime +:= 1; end if;

        if n <= 25 then
            print(lpad(str n, 2), "  ",
                  lpad(str tot, 2), "  ",
                  if tot = n-1 then "prime" else "" end if);
        end if;

        if n in [1000,10000,100000,1000000] then
            print(lpad(str prime,8), "primes up to" + lpad(str n,8));
        end if;
    end loop;

    proc totient(n);
        tot := n;
        i := 2;
        loop while i*i <= n do
            if n mod i = 0 then
                loop while n mod i = 0 do
                    n div:= i;
                end loop;
                tot -:= tot div i;
            end if;
            if i=2 then i:=3;
            else i+:=2;
            end if;
        end loop;
        if n>1 then
            tot -:= tot div n;
        end if;
        return tot;
    end proc;
end program;