You are given an array a consisting of n positive integers. You have to choose a positive integer d and paint all elements into two colors. All elements which are divisible by d will be painted red, and all other elements will be painted blue.

The coloring is called beautiful if there are no pairs of adjacent elements with the same color in the array. Your task is to find any value of d which yields a beautiful coloring, or report that it is impossible.

Input

The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of testcases.

The first line of each testcase contains one integer n (2 ≤ n ≤ 100) — the number of elements of the array.

The second line of each testcase contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^{18}).

Output

For each testcase print a single integer. If there is no such value of d that yields a beautiful coloring, print 0. Otherwise, print any suitable value of d (1 ≤ d ≤ 10^{18}).

Example

Input


5
5
1 2 3 4 5
3
10 5 15
3
100 10 200
10
9 8 2 6 6 2 8 6 5 4
2
1 3


Output


2
0
100
0
3
1
5
6 5 12 5 16
 1
5
3 5 6 11 2

2
 0

import java.util.*;
import java.io.*;
import java.math.*;
import java.lang.*;

public class c {
    
    // static int mod = 998244353;
    static int mod = 1000000007;

    public static class Reader {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;
 
        public Reader()
        {
            din = new DataInputStream(System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }
 
        public Reader(String file_name) throws IOException
        {
            din = new DataInputStream(
                new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }
 
        public String readLine() throws IOException
        {
            byte[] buf = new byte[64]; // line length
            int cnt = 0, c;
            while ((c = read()) != -1) {
                if (c == '\n') {
                    if (cnt != 0) {
                        break;
                    }
                    else {
                        continue;
                    }
                }
                buf[cnt++] = (byte)c;
            }
            return new String(buf, 0, cnt);
        }
 
        public int nextInt() throws IOException
        {
            int ret = 0;
            byte c = read();
            while (c <= ' ') {
                c = read();
            }
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
 
            if (neg)
                return -ret;
            return ret;
        }
 
        public long nextLong() throws IOException
        {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }
 
        public double nextDouble() throws IOException
        {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
 
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
 
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
 
            if (neg)
                return -ret;
            return ret;
        }
 
        private void fillBuffer() throws IOException
        {
            bytesRead = din.read(buffer, bufferPointer = 0,
                                 BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }
 
        private byte read() throws IOException
        {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }
 
        public void close() throws IOException
        {
            if (din == null)
                return;
            din.close();
        }
    }

    public static void main(String[] args) throws Exception {
        Reader scn = new Reader();
        PrintWriter pw = new PrintWriter(System.out);
        int t = scn.nextInt();
        outer : while(t-->0){
            int n = scn.nextInt();
            long[] arr = new long[n];
            for(int i=0; i<n; i++){
                arr[i] = scn.nextLong();
            }
            ArrayList<Long> odd = new ArrayList<>();
            ArrayList<Long> even = new ArrayList<>();
            for(int i=0; i<n; i+=2){
                even.add(arr[i]);
            }
            for(int i=1; i<n; i+=2){
                odd.add(arr[i]);
            }
            long gcdOdd = odd.get(0);
            for(int i=1; i<odd.size(); i++){
                gcdOdd = gcd(gcdOdd, odd.get(i));
            }
            long gcdEven = even.get(0);
            for(int i=1; i<even.size(); i++){
                gcdEven = gcd(gcdEven, even.get(i));
            }
            if(gcdOdd == gcdEven){
                pw.println(0);
                continue outer;
            }
            if(gcdEven > gcdOdd){
                for(long val : odd){
                    if(val % gcdEven == 0){
                        pw.println(0);
                        continue outer;
                    }
                }
                pw.println(gcdEven);
                continue outer;
            }else{
                for(long val : even){
                    if(val % gcdOdd == 0){
                        pw.println(0);
                        continue outer;
                    }
                }
                pw.println(gcdOdd);
                continue outer;
            }
        }
        pw.close();
    }

    public static class Pair{
        int x;
        int y;

        Pair(int x, int y){
            this.x = x;
            this.y = y;
        }
    }

    private static void sort(int[] arr) {
        List<Integer> list = new ArrayList<>();
        for (int i=0; i<arr.length; i++){
            list.add(arr[i]);
        }
        Collections.sort(list); // collections.sort uses nlogn in backend
        for (int i = 0; i < arr.length; i++){
            arr[i] = list.get(i);
        }
    }

    private static void sort(long[] arr) {
        List<Long> list = new ArrayList<>();
        for(int i=0; i<arr.length; i++){
            list.add(arr[i]);
        }
        Collections.sort(list); // collections.sort uses nlogn in backend
        for (int i = 0; i < arr.length; i++){
            arr[i] = list.get(i);
        }
    }

    // private static void sort(Pair[] arr) {
    //     List<Pair> list = new ArrayList<>();
    //     for(int i=0; i<arr.length; i++){
    //         list.add(arr[i]);
    //     }
    //     Collections.sort(list); // collections.sort uses nlogn in backend
    //     for (int i = 0; i < arr.length; i++){
    //         arr[i] = list.get(i);
    //     }
    // }

    private static void reverseSort(int[] arr){
        List<Integer> list = new ArrayList<>();
        for (int i=0; i<arr.length; i++){
            list.add(arr[i]);
        }
        Collections.sort(list, Collections.reverseOrder()); // collections.sort uses nlogn in backend
        for (int i = 0; i < arr.length; i++){
            arr[i] = list.get(i);
        }
    }

    private static void reverseSort(long[] arr){
        List<Long> list = new ArrayList<>();
        for (int i=0; i<arr.length; i++){
            list.add(arr[i]);
        }
        Collections.sort(list, Collections.reverseOrder()); // collections.sort uses nlogn in backend
        for (int i = 0; i < arr.length; i++){
            arr[i] = list.get(i);
        }
    }

    private static void reverseSort(ArrayList<Integer> list){
        Collections.sort(list, Collections.reverseOrder());
    }

    private static int lowerBound(int[] arr, int x){
        int n = arr.length, si = 0, ei = n - 1;
        while(si <= ei){
            int mid = si + (ei - si)/2;
            if(arr[mid] == x){
                if(mid-1 >= 0 && arr[mid-1] == arr[mid]){
                    ei = mid-1;
                }else{
                    return mid;
                }
            }else if(arr[mid] > x){
                ei = mid - 1; 
            }else{
                si = mid+1;
            }
        }
        return si; 
    }

    private static int upperBound(int[] arr, int x){
        int n = arr.length, si = 0, ei = n - 1;
        while(si <= ei){
            int mid = si + (ei - si)/2;
            if(arr[mid] == x){
                if(mid+1 < n && arr[mid+1] == arr[mid]){
                    si = mid+1;
                }else{
                    return mid + 1;
                }
            }else if(arr[mid] > x){
                ei = mid - 1; 
            }else{
                si = mid+1;
            }
        }
        return si; 
    }

    private static int upperBound(ArrayList<Integer> list, int x){
        int n = list.size(), si = 0, ei = n - 1;
        while(si <= ei){
            int mid = si + (ei - si)/2;
            if(list.get(mid) == x){
                if(mid+1 < n && list.get(mid+1) == list.get(mid)){
                    si = mid+1;
                }else{
                    return mid + 1;
                }
            }else if(list.get(mid) > x){
                ei = mid - 1; 
            }else{
                si = mid+1;
            }
        }
        return si; 
    }

    // (x^y)%p in O(logy)
    private static long power(long x, long y){
        long res = 1; 
        x = x % mod;
        while(y > 0){
            if ((y & 1) == 1){
                res = (res * x) % mod;
            }
            y = y >> 1; 
            x = (x * x) % mod;
        }
        return res;
    }

    public static boolean nextPermutation(int[] arr) {
        if(arr == null || arr.length <= 1){
            return false;
        }
        
        int last = arr.length-2;
        while(last >= 0){
            if(arr[last] < arr[last+1]){
                break;
            }
            last--;
        }

        if (last < 0){
              return false;
        }
        
        if(last >= 0){
            int nextGreater = arr.length-1;
            for(int i=arr.length-1; i>last; i--){
                if(arr[i] > arr[last]){
                    nextGreater = i;
                    break;
                }
            }
            swap(arr, last, nextGreater);
        }
        
        reverse(arr, last+1, arr.length-1);
        return true;
    }
    
    private static void swap(int[] arr, int i, int j){
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }
    
    private static void reverse(int[] arr, int i, int j){
        while(i < j){
            swap(arr, i++, j--);
        }
    }

    private static String reverseStr(String s){
        StringBuilder sb = new StringBuilder(s);
        return sb.reverse().toString();
    }

    // TC- O(logmax(a,b))
    private static int gcd(int a, int b) {
        if(a == 0){
            return b;
        }
        return gcd(b%a, a);
    }

    private static long gcd(long a, long b) {
        if(a == 0L){
            return b;
        }
        return gcd(b%a, a);
    }

    private static long lcm(long a, long b) {
        return a / gcd(a, b) * b;
    }

    // TC- O(logmax(a,b))
    private static int lcm(int a, int b) {
        return a / gcd(a, b) * b;
    }

    private static long inv(long x){
        return power(x, mod - 2);
    }

    private static long summation(long n){
        return (n * (n + 1L)) >> 1;
    } 
}