#include <bits/stdc++.h>
using namespace std;
 
#define ll long long
#define ull unsigned long long
#define ld long double
 
void Free_palestine() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}
 
const int N = 2e5 + 5;
const int MOD = 1e9 + 7;
 
signed main(){
  Free_palestine();
 
  int n; cin>>n;
  int freq[26]={};
  while(n--){
  	char x;
  	cin>>x;
  	freq[x-'a']++;
 
  }
  for(int i=0;i<26;i++){
  	if(freq[i]){
  		while(freq[i]--){
  			cout<<char(i+'a');
  		}
  	}
  }
    return 0;
}

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NQplZ3lwdAo=

5
egypt