set &number 4 set &stop 0 fun -double !mod -double &in -double &modulus lesser $in $modulus &store not $store &store if $store %downloop lesser $in 0 &store if $store %uploop jump %end @downloop subtract $in $modulus &in lesser $in $modulus &store not $store &store if $store %downloop jump %end @uploop add $in $modulus &in lesser $in 0 &store if $store %uploop jump %end @end return $in endfun @loop equal $number 1 &stop if $stop %end jump %loop @end end 0