program stern_brocot_sequence;
    s := stern(1200);

    print("First 15 elements:", s(1..15));

    loop for n in [1..10] with 100 do
        if exists k = s(i) | k = n then
            print("First", n, "at", i);
        end if;
    end loop;

    gcds := [gcd(s(i-1), s(i)) : i in [2..1000]];

    if exists g = gcds(i) | g /= 1 then
        print("The GCD of the pair at", i, "is not 1.");
    else
        print("All GCDs of consecutive pairs up to 1000 are 1.");
    end if;

    proc stern(n);
        s := [1, 1];
        loop for i in [2..n div 2] do
            s(i*2-1) := s(i) + s(i-1);
            s(i*2) := s(i);
        end loop;
        return s;
    end proc;

    proc gcd(a,b);
        loop while b/=0 do
            [a, b] := [b, a mod b];
        end loop;
        return a;
    end proc;
end program;