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
/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.lang.reflect.Array;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 *
 * @author Artem_Mikhalevitch
 */
public class Main extends ASolver {

    int n;
    Set set;

    public static void main(String[] args) throws ParseException {
        Main s = new Main();
        s.init();
        if (s.readData()) {
            s.solve();
            s.writeData("" + s.solve());
        }
    }

    @Override
    public void init() {
        super.init();
    }

    @Override
    public boolean readData() {
        try {
            n = nextInt();
            set = new TreeSet();
            int i=0;
            while(i++<n){
               set.add(nextInt());
               
            }
            
        } catch (Exception ex) {
            System.out.println(ex.getCause());
            System.out.println(ex.getMessage());
            return false;
        }
        return true;
    }

    public double[] sort(double[] mas1, double[] mas2) {
        int l1 = mas1.length;
        int l2 = mas2.length;
        double[] result = new double[l1 + l2];
        int i1 = 0, i2 = 0;
        int i = 0;
        for (i = 0; i1 < l1 && i2 < l2; i++) {
            if (mas1[i1] <= mas2[i2]) {
                result[i] = mas1[i1++];
            } else {
                result[i] = mas2[i2++];
            }
        }
        for (int j = i; i1 < l1; j++) {
            result[j] = mas1[i1++];
        }
        for (int j = i; i2 < l2; j++) {
            result[j] = mas2[i2++];
        }
        return result;
    }

    public int solve() {
        Iterator<Integer> it=set.iterator();
        int result = it.next();
        while(it.hasNext()){
            if(it.next()%result!=0){
                result=-1;
                break;
            }
        }
        
        return result;
    }
}

abstract class ASolver {

    protected StringTokenizer tokens;
    protected BufferedReader input;
    protected PrintWriter output;

    public void init() {
        input = new BufferedReader(new InputStreamReader(System.in));
    }

    public abstract boolean readData();

    public void writeData(String result) {
        System.out.println(result);
    }

    public void writeData(int result) {
        System.out.println(result);
    }

    public void writeData(long result) {
        System.out.println(result);
    }

    public int nextInt() throws IOException {
        return Integer.parseInt(next());
    }

    public double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }

    public long nextLong() throws IOException {
        return Long.parseLong(next());
    }

    public String next() throws IOException {
        while (tokens == null || !tokens.hasMoreTokens()) {
            tokens = new StringTokenizer(input.readLine());
        }
        return tokens.nextToken();
    }

    public String nextLine() throws IOException {
        while (tokens == null || !tokens.hasMoreTokens()) {
            tokens = new StringTokenizer(input.readLine(), "\n");
        }
        return tokens.nextToken();
    }

    public long infinityImitator(long a, long b) {
        if (a == Long.MIN_VALUE) {
            return Long.MIN_VALUE;
        } else {
            return a + b;
        }
    }

    public int infinityImitator(int a, int b) {
        if (a == Integer.MIN_VALUE) {
            return Integer.MIN_VALUE;
        } else {
            return a + b;
        }
    }

    /*
     * public long max(long... a) { long result = Long.MIN_VALUE; for (int i =
     * 0; i < a.length; i++) { result = Math.max(result, a[i]); } return result;
     * }
     */
    public int indexMax(int... a) {
        int result = 0;
        int index = -1;
        int length = a.length;
        for (int i = 0; i < length; i++) {
            if (a[i] > result) {
                result = a[i];
                index = i;
            }
        }
        return index;
    }

    public int indexMax(long... a) {
        long result = 0;
        int index = -1;
        int length = a.length;
        for (int i = 0; i < length; i++) {
            if (a[i] > result) {
                result = a[i];
                index = i;
            }
        }
        return index;
    }

    public int max(int... a) {
        int result = Integer.MIN_VALUE;
        for (int i = 0; i < a.length; i++) {
            result = Math.max(result, a[i]);
        }
        return result;
    }

    public long max(long... a) {
        long result = Integer.MIN_VALUE;
        for (int i = 0; i < a.length; i++) {
            result = Math.max(result, a[i]);
        }
        return result;
    }
}
