【Henu ACM Round#24 A】k-String

#include <bits/stdc++.h>
#define LL long long
#define rep1(i,a,b) for (int i = a;i <= b;i++)
#define rep2(i,a,b) for (int i = a;i >= b;i--)
#define all(x) x.begin(),x.end()
#define pb push_back
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
using namespace std;

const double pi = acos(-1);
const int dx[4] = {0,0,1,-1};
const int dy[4] = {1,-1,0,0};
const int N = 1000;

int k,num[N+10];
char s[N+10];
string ss;

int main(){
    #ifdef LOCAL_DEFINE
        freopen("rush_in.txt", "r", stdin);
    #endif
    ios::sync_with_stdio(0),cin.tie(0);
    cin >> k;
    cin >> s;
    int len = strlen(s);
    rep1(i,0,len-1){
        num[s[i]-'a']++;
    }
    for (int i = 0;i < 26;i++)
        if (num[i]%k!=0){
            return cout<<-1<<endl,0;
        }else{
            for (int j = 1;j <= num[i]/k;j++)
                ss+=((char)(i+'a'));
        }
    if (len%k!=0){
        return cout<<-1<<endl,0;
    }
    for (int i = 1;i <= k;i++) cout<<ss;
    return 0;
}