Answer required for this program

Hi all

can anyone gimme the answer for this program

REPORT demo_mod_tech_example_2.

DATA: num TYPE i VALUE 5,

fac TYPE i VALUE 0.

PERFORM fact USING num CHANGING fac.

WRITE: / 'Factorial of', num, 'is', fac.

FORM fact

USING value(f_num) TYPE i

CHANGING f_fact TYPE i.

f_fact = 1.

WHILE f_num GE 1.

f_fact = f_fact * f_num.

f_num = f_num - 1.

ENDWHILE.

ENDFORM.