#include <iostream>
#include <algorithm>
using namespace std;
int main()
{
    int n,m;
    string a,b;
    cin>>n>>m;
    cin>>a>>b;
    sort(b.begin(),b.end(),greater<int>());
    cout<<b<<endl;
    string::iterator k=b.begin();
    cout<<*k;
    vector<int>::iterator k;           
}