c-gcc, 98 bytes

Result

WA

Code [DL]

char s[1],i=100;main(){while(i--){read(0,&s,1);s[s]++;}while(58-i++){while(s[i]--)write(1,&i,1);}}

stdin

7506298253283188305030401795971018750665305293402206934774523933413303735092213546520375701874031066

stdout

stderr

/volume/CODE.c:1:17: warning: return type defaults to ‘int’ [-Wimplicit-int]
 char s[1],i=100;main(){while(i--){read(0,&s,1);s[s]++;}while(58-i++){while(s[i]--)write(1,&i,1);}}
                 ^
/volume/CODE.c: In function ‘main’:
/volume/CODE.c:1:35: warning: implicit declaration of function ‘read’ [-Wimplicit-function-declaration]
 char s[1],i=100;main(){while(i--){read(0,&s,1);s[s]++;}while(58-i++){while(s[i]--)write(1,&i,1);}}
                                   ^
/volume/CODE.c:1:49: error: array subscript is not an integer
 char s[1],i=100;main(){while(i--){read(0,&s,1);s[s]++;}while(58-i++){while(s[i]--)write(1,&i,1);}}
                                                 ^
/volume/CODE.c:1:77: warning: array subscript has type ‘char’ [-Wchar-subscripts]
 char s[1],i=100;main(){while(i--){read(0,&s,1);s[s]++;}while(58-i++){while(s[i]--)write(1,&i,1);}}
                                                                             ^
/volume/CODE.c:1:83: warning: implicit declaration of function ‘write’ [-Wimplicit-function-declaration]
 char s[1],i=100;main(){while(i--){read(0,&s,1);s[s]++;}while(58-i++){while(s[i]--)write(1,&i,1);}}
                                                                                   ^
/home/esolang/bin/c-gcc: line 4: /tmp/code: No such file or directory

strace