codeforce - K-String

#include<bits/stdc++.h>
using namespace std;
#define fastread()(ios_base::sync_with_stdio(false),cin.tie(NULL));
#define pb push_back
#define khela_hobe int main()
#define bahir_ho return 0
#define f first
#define s second
khela_hobe
{
    fastread();
    int n;
    cin>>n;
    string s,ans;
    cin>>s;
    bool flag=true;
    map<char,int>mp;
    map<char,int>:: iterator it;
    for(int i=0; i<s.size(); i++)
    {
        mp[s[i]]++;
    }
    for(it= mp.begin(); it!=mp.end(); it++)
    {
        if(it->s%n!=0)
        {
            flag=false;
            break;
        }

        for(int i=0; i<it->s/n; i++)
        {
            ans.pb(it->f);
        }
        //cout<<<<endl;
    }
    if(flag)
        for(int i=0; i<n; i++)
            cout<<ans;
    else
        cout<<"-1";
    bahir_ho;
}