section .data
a db  'yukicoder'
b db  0

section .text
global _start
_start:
  ; read
  mov rsi, b
  mov rdx, 20
  syscall
  ; ?
  call  c
  ; write
  mov rax, 1
  mov rdi, rax
  lea rsi, [a + r10]
  mov rdx, rax
  syscall
  ; exit
  mov rax, 60
  xor rdi, rdi
  syscall

c:
  mov al, [b + r10]
  mov dil, al
  cmp dil, 63
  jz  cr
  inc r10
  loop  c
cr:
  ret