c-gcc, 161 bytes

Result

WA

Code [DL]

#include<stdio.h>
char l[256];char c;int i,j;int main(){for (i=0;i<100;i++){read(0,&c,1);l[c]++;}for (i=48;i<58;i++)for(j=0;j<l[i];j++)printf("%c",i);return 0;}

stdin

1619930042362874406299370114508411390932979013088354960124158664350406871464582602068780620108516478

stdout

stderr

/volume/CODE: file not recognized: File format not recognized
collect2: error: ld returned 1 exit status
/home/esolang/bin/c-gcc: line 4: /tmp/code: No such file or directory

strace