vim, 25 bytes

Result

WA

Code [DL]

:s/\(.\)/\1
/g|sor|%j!
ZZ

Disassembly

:s/\(.\)/\1<CR>/g|sor|%j!<NL>ZZ

stdin

8902255753719842009306598956040807209018095476952470453934110058200678450383202937659833900664816149

stdout

8902255753719842009306598956040807209018095476952470453934110058200678450383202937659833900664816149

stderr

strace