题解

#include<bits/stdc++.h>
using namespace std;
int main(){
	string a,b,c;
	cin>>a;
	for(int i=0;i<a.size();i++){
		if(i%2==0)b+=a[i];
		else c+=a[i];
	}
	cout<<max(b,c)<<min(b,c);
	return 0;
}