\Calculate the Multiplicative Digital Root (MDR) and
    \ Multiplicative Persistence (MP) of N
    procedure GetMDR ( N, MDR, MP );
    integer   N, MDR, MP, V;
    begin
        MP(0)  := 0;
        MDR(0) := abs( N );
        while MDR(0) > 9 do begin
           V   := MDR(0);
           MDR(0) := 1;
           repeat
               MDR(0) := MDR(0) * rem( V / 10 );
               V   := V / 10;
           until V = 0;
           MP(0) := MP(0) + 1;
        end; \while_mdr_gt_9
    end; \GetMDR

    define  RequiredMDRs = 5;
    integer FirstFew ( 9+1, 1+RequiredMDRs );
    integer MDRFound ( 9+1 );
    integer TotalFound, FoundPos, RequiredTotal, N, I, V, L;
    integer MDR, MP;
    begin
        \task test cases
        Text(0, "       N MDR MP^m^j" );
        L := [ 123321, 7739, 893, 899998 ];
        for N := 0 to 3 do begin
            GetMDR( L(N), @MDR, @MP );
            Format(8, 0);  RlOut(0, float(L(N)));
            Format(4, 0);  RlOut(0, float(MDR));
            Format(3, 0);  RlOut(0, float(MP));
            CrLf(0)
        end; \for_N
        \find the first 5 numbers with each possible MDR
        begin
            for I := 0 to 9 do MDRFound( I ) := 0;
            TotalFound    := 0;
            RequiredTotal := 10 * RequiredMDRs;
            N             := -1;
            while TotalFound < RequiredTotal do begin
                N := N + 1;
                GetMDR( N, @MDR, @MP );
                if MDRFound( MDR ) < RequiredMDRs then begin
                    \Found another number with this MDR and haven't found enough
                    TotalFound                       := TotalFound + 1;
                    MDRFound( MDR )                  := MDRFound( MDR ) + 1;
                    FirstFew( MDR, MDRFound( MDR ) ) := N
                end \if_Found_another_MDR
            end; \while_TotalFound_lt_RequiredTotal
            \print the table of MDRs and numbers
            Text(0, "MDR: [N0..N4]^m^j" );
            Text(0, "===  ========^m^j" );
            for V := 0 to 9 do begin
                ChOut(0, ^ );  IntOut(0, V);  Text(0, ": [");
                for FoundPos := 1 to RequiredMDRs do begin
                    if FoundPos > 1 then Text( 0, ", " );
                    IntOut( 0, FirstFew( V, FoundPos ) )
                end; \for_FoundPos
                Text(0, "]^m^j")
            end \for_v
        end
    end