#include <iostream>
#include <cmath>
using namespace std;
int main(){
int k;
cin>>k;
string a;
cin>>a;
int count[26];
int l=a.size();
if(l%k!=0 || l<k){
cout<<-1;
return 0;
}
for(int i=0;i<26;i++)
count[i]=0;
for(int i=0;i<l;i++){
count[a[i]-97]++;
}
for(int i=0;i<26;i++){
if(count[i]%k!=0 && count[i]!=0){
cout<<-1;
return 0;
}}
int pos=0;
for(int i=0;i<l;pos++){
if(count[pos]%k==0 && count[pos]!=0){
for(int j=0;j<count[pos]/k;j++)
cout<<(char)(pos+97);
i++;
}
if(pos==25)
pos=-1;
}
return 0;
}
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