extern printf
extern scanf
global main

section .data
liczba dq 0
fmt db "%d",0
fmt2 db "%d",10,0

section .text

main:

mov r12,1
mov r13,1

mov rdi,fmt
mov rsi,liczba
xor rax,rax
call scanf

petla:
imul r12,r13
cmp r13,qword[liczba]
je koniec
inc r13
jmp petla

koniec:
mov rdi,fmt2
mov rsi,r12
xor rax,rax
call printf

mov rax,1
mov rbx,0
int 80h