#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main()
{
string str="";
cin>>str;
vector <char > mv;
for(int i=0;i<str.length();i++)
{
if(str[i]>='A'&&str[i]<='Z')
{
mv.push_back(str[i]);
str[i]+=32;
}
}
sort(str.begin(),str.end());
for(int i=0;i<mv.size();i++)
for(int j=0;j<str.length();j++)
{
if(str[j]>='A'&&str[j]<='Z')
continue;
if(str[j]==(mv[i]+32))
{
str[j] -= 32;
break;
}
}
cout<<str<<"\n";
return 0;
}
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