Block 4806
: FIB ( n -- fib )
  DUP 0= IF DROP 0 EXIT THEN
  DUP 1 = IF DROP 1 EXIT THEN
  0 1 ROT 0 DO SWAP OVER + LOOP DROP ;

: FACTORIAL ( n -- n! )
  DUP 2 < IF DROP 1 EXIT THEN
  DUP 1 - FACTORIAL * ;

: MAIN
  1000 0 DO
    10 FIB DROP
    5 FACTORIAL DROP
  LOOP
;
MAIN