include <bits/stdc++.h>

using namespace std;

int main() {

string a;
getline(cin, a);
string b;
for (int i = 0; i < a.length(); i++) {
	if (a[i] % 3 == 0)
		continue;
	b = b + a[i];
}
sort(b.begin(), b.end());
cout << b;
return 0;

}