Ksusha is a beginner coder. Today she starts studying arrays. She has array a1, a2, ..., an, consisting of n positive integers.

Her university teacher gave her a task. Find such number in the array, that all array elements are divisible by it. Help her and find the number!

Input

The first line contains integer n (1 ≤ n ≤ 105), showing how many numbers the array has. The next line contains integers a1, a2, ..., an (1 ≤ ai ≤ 109) — the array elements.

Output

Print a single integer — the number from the array, such that all array elements are divisible by it. If such number doesn't exist, print -1.

If there are multiple answers, you are allowed to print any of them.

Examples

Input

3
2 2 4


Output

2


Input

5
2 1 3 1 6


Output

1


Input

3
2 3 5


Output

-1
import java.awt.Point;
import java.io.*;
import java.math.BigInteger;
import java.util.*;
import java.util.Map.Entry;

import static java.lang.Math.*;

public class Solve implements Runnable{
    
final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;
    
    BufferedReader in;
    PrintWriter out;
    StringTokenizer tok = new StringTokenizer("");
    
    void init() throws FileNotFoundException{
        if (ONLINE_JUDGE){
            in = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
        }else{
            in = new BufferedReader(new FileReader("input.txt"));
            out = new PrintWriter("output.txt");
        }
    }
    
    String readString() throws IOException{
        while(!tok.hasMoreTokens()){
            try{
                tok = new StringTokenizer(in.readLine());
            }catch (Exception e){
                return null;
            }
        }
        return tok.nextToken();
    }
    
    int readInt() throws IOException{
        return Integer.parseInt(readString());
    }
    
    long readLong() throws IOException{
        return Long.parseLong(readString());
    }
    
    double readDouble() throws IOException{
        return Double.parseDouble(readString());
    }
    
    public static void main(String[] args){
        new Thread(null, new Solve(), "", 256 * (1L << 20)).start();
    }
    
    long timeBegin, timeEnd;

    void time(){
        timeEnd = System.currentTimeMillis();
        System.err.println("Time = " + (timeEnd - timeBegin));
    }
    
    void debug(Object... objects){
        if (!ONLINE_JUDGE){
            for (Object o: objects){
                System.err.println(o.toString());
            }
        }
    }
    
    int sm(int x){
        if (x==1) return 0;else return 1;
    }
    
    int gcd(int a,int b){
        if (b==0) return a;
        else{
            return gcd(b,a%b);
        }
    }
    
    
   
    
    
    
    void solve() throws IOException{    
        int n=readInt();
        int[] a=new int[n];
        for (int i=0;i<n;i++){
            a[i]=readInt();
        }
        
        if (n==1){
            out.println(a[0]);
            return;
        }
        
        
        int naim=gcd(a[0],a[1]);
        for (int i=2;i<n;i++){
            naim=gcd(naim,a[i]);
        }
        Arrays.sort(a);
        if (Arrays.binarySearch(a, naim)>=0){
            System.out.println(naim);
            return;         
        }
        else System.out.println("-1");
        
        


        
    }
        
        
        
    
    
    public void run(){
        try{
            timeBegin = System.currentTimeMillis();
            init();
            solve();
            out.close();
            time();
        }catch (Exception e){
            e.printStackTrace(System.err);
            System.exit(-1);
        }
    }
    
    
}