function integer Lagarias (N); \Lagarias arithmetic derivative
integer N;
integer F, Q;

        function integer SmallPF (J, K); \Smallest prime factor
        integer J, K;
        return if rem(J/K) = 0 then K else SmallPF(J, K+1);

begin
if N < 0
then return -Lagarias (-N)
else if N = 0 or N = 1
then return 0
else    begin
        F := SmallPF (N, 2);  Q := N / F;
        return if Q = 1
        then 1
        else Q * Lagarias (F)  +  F * Lagarias (Q)
        end;
end \Lagarias\ ;

integer N;
begin
    for N:= -99 to 100 do begin
        IntOut(0, Lagarias(N) );
        if rem(N/10) = 0 then CrLf(0) else ChOut(0, 9\tab\);
    end;
end