rail, 65 bytes

Result

WA

Code [DL]

$ 'x'
 \
  \-(!a!)(!b!)(a)(b)#

$ 'main'
 \
  \-[hoge][piyo]o#
  

stdin

6892604904393289256867046915026459787141044638718256083646624817068627320462778029977275751001082529

stdout

piyo

stderr

strace