section .data
yukicoder  db  'yukicoder'

section .bss
buf resb  0

section .text
global _start

_start:
  call  read
  call  check
  call  write
  call  exit

read:
  xor r10, r10
  xor rax, rax
  xor rdi, rdi
  mov rsi, buf
  mov rdx, 10
  syscall
  ret

check:
  mov al, [buf + r10]
  mov dil, al
  cmp dil, 63
  jz  check_ret
  inc r10
  loop  check
check_ret:
  ret

write:
  mov rax, 1
  mov rdi, 1
  lea rsi, [yukicoder + r10]
  mov rdx, 1
  syscall
  ret

exit:
  mov rax, 60
  xor rdi, rdi
  syscall