#include <algorithm>
#include <iostream>
#include <stdio.h>
#include <string>
using namespace std;
int main() {
    string s;
    int f[100005];
    bool a[100005];
    cin >> s;
    for (int i = 0; i < s.size(); i++) f[i] = s[i] - '0';
    sort(f, f + s.size());
    for (i = 0; i < s.size(); i++) {
        if (f[i] + '0' > 'Z' || f[i] + '0' < 'A')
            printf("%c", f[i] + '0'), a[i] = 1;
    }
    for (i = 0; i < s.size(); i++) {
        if (!a[i]) {
            printf("%c", f[i] + '0');
        }
    }
    return 0;
}

/sandbox/1/a.cpp: In function 'int main()':
/sandbox/1/a.cpp:14:9: error: name lookup of 'i' changed for ISO 'for' scoping [-fpermissive]
     for(i=0;i<s.size();i++)
         ^
/sandbox/1/a.cpp:14:9: note: if you use '-fpermissive' G++ will accept your code