bash-pure, 59 bytes

Result

WA

Code [DL]

while read -n1 c;do a[c]+=$c;done
echo $(IFS=;echo ${a[*]})

stdin

5885371477501224874906279461235307854188805404012992101294428660011250376533807861384380564592423085

stdout

0000000000000 1111111111 22222222222 333333333 444444444444 55555555555 6666666 77777777 8888888888888 999999

stderr

/bin/bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8)

strace