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.util.*;
import java.util.regex.*;
import static java.lang.Math.*;
import static java.util.Arrays.*;
import static java.lang.Integer.*;
import static java.lang.Double.*;
import static java.util.Collections.*;
import java.io.*;

public class _299_A_Ksusha_and_Array {
	//->solution screencast http://youtu.be/oHg5SJYRHA0
	public void solve() {
		int n = ni();
		int ar[]=na(n);
		if(n==1){
			out.println(ar[0]);
			return;
		}
		HashSet<Integer> hs = new HashSet<Integer>();
		for (int i = 0; i < ar.length; i++) {
			hs.add(ar[i]);
		}
		int[] ar1 = new int [hs.size()];
		int x=0;
		for (int i : hs) {
			ar1[x++]=i;
		}
		radixSort(ar1);
		pr(ar1);
		for (int i = 0; i < ar1.length; i++) {
			for (int j = i+1; j < ar1.length; j++) {
				if(ar1[j]%ar1[i]!=0)
					break;
				if(j==ar1.length-1){
					out.println(ar1[i]);
					return;
				}
			}
		}
		out.println(-1);
	}
	public static int[] radixSort(int[] f)
	{
		int[] to = new int[f.length];
		{
			int[] b = new int[65537];
			for(int i = 0;i < f.length;i++)b[1+(f[i]&0xffff)]++;
			for(int i = 1;i <= 65536;i++)b[i]+=b[i-1];
			for(int i = 0;i < f.length;i++)to[b[f[i]&0xffff]++] = f[i];
			int[] d = f; f = to;to = d;
		}
		{
			int[] b = new int[65537];
			for(int i = 0;i < f.length;i++)b[1+(f[i]>>>16)]++;
			for(int i = 1;i <= 65536;i++)b[i]+=b[i-1];
			for(int i = 0;i < f.length;i++)to[b[f[i]>>>16]++] = f[i];
			int[] d = f; f = to;to = d;
		}
		return f;
	}
    int gcd(int a, int b) {
        if (b == 0) {
            return a;
        }
        return gcd(b, a % b);
    }
	
	// IO methods
		
	void run() throws Exception {
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		pr(System.currentTimeMillis() - s + "ms");
	}
	public static void main(String[] args) throws Exception {new _299_A_Ksusha_and_Array().run();}

	InputStream in=System.in;
	PrintWriter out=new PrintWriter(System.out);
	
	private boolean oj = System.getProperty("ONLINE_JUDGE") != null;
	private byte[] inbuf = new byte[1024];
	private int lenbuf = 0, ptrbuf = 0;

	private int readByte() {
		if (lenbuf == -1)
			throw new InputMismatchException();
		if (ptrbuf >= lenbuf) {
			ptrbuf = 0;
			try {
				lenbuf = in.read(inbuf);
			} catch (IOException e) {
				throw new InputMismatchException();
			}
			if (lenbuf <= 0)
				return -1;
		}
		return inbuf[ptrbuf++];
	}

	private boolean isSpaceChar(int c) {return !(c >= 33 && c <= 126);}
	private int skip() {int b;while ((b = readByte()) != -1 && isSpaceChar(b));return b;}

	public String ns() {
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != // ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	public char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	public char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	public int[] na(int n) {
		int[] a = new int[n];
		for (int i = 0; i < n; i++)
			a[i] = ni();
		return a;
	}
	
	
	public int ni() {
		int num = 0, b;
		boolean minus = false;
		while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
			;
		if (b == '-') {
			minus = true;
			b = readByte();
		}

		while (true) {
			if (b >= '0' && b <= '9') {
				num = num * 10 + (b - '0');
			} else {
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	public long nl(){
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	void pr(Object... ob) {if (!oj)System.out.println(Arrays.deepToString(ob).replace("],", "],\n"));}
}

