During the research on properties of the greatest common divisor (GCD) of a set of numbers, Ildar, a famous mathematician, introduced a brand new concept of the weakened common divisor (WCD) of a list of pairs of integers.

For a given list of pairs of integers (a_1, b_1), (a_2, b_2), ..., (a_n, b_n) their WCD is arbitrary integer greater than 1, such that it divides at least one element in each pair. WCD may not exist for some lists.

For example, if the list looks like [(12, 15), (25, 18), (10, 24)], then their WCD can be equal to 2, 3, 5 or 6 (each of these numbers is strictly greater than 1 and divides at least one number in each pair).

You're currently pursuing your PhD degree under Ildar's mentorship, and that's why this problem was delegated to you. Your task is to calculate WCD efficiently.

Input

The first line contains a single integer n (1 ≤ n ≤ 150 000) — the number of pairs.

Each of the next n lines contains two integer values a_i, b_i (2 ≤ a_i, b_i ≤ 2 ⋅ 10^9).

Output

Print a single integer — the WCD of the set of pairs. 

If there are multiple possible answers, output any; if there is no answer, print -1.

Examples

Input

3
17 18
15 24
12 15


Output

6

Input

2
10 16
7 17


Output

-1


Input

5
90 108
45 105
75 40
165 175
33 30


Output

5

Note

In the first example the answer is 6 since it divides 18 from the first pair, 24 from the second and 12 from the third ones. Note that other valid answers will also be accepted.

In the second example there are no integers greater than 1 satisfying the conditions.

In the third example one of the possible answers is 5. Note that, for example, 15 is also allowed, but it's not necessary to maximize the output.
import org.omg.CORBA.INTERNAL;

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

public class WCD {
    static Scanner sc = new Scanner(System.in);
    static PrintWriter pw = new PrintWriter(System.out), pw2 = new PrintWriter(System.out);
    static HashSet<Integer> findDivisors(int x){
        HashSet<Integer> divisors=new HashSet<>();
        for(int i=2;i*i<=x;i++){
            if(x%i==0){
                if(x/i==i)
                    divisors.add(i);
                else {
                    divisors.add(i);
                    divisors.add(x/i);
                }
            }
        }
        divisors.add(x);
        return divisors;
    }  
    public static void main(String[] args) throws IOException {
        int n=sc.nextInt();
        int x=sc.nextInt();
        int y=sc.nextInt();
        HashSet<Integer> divisors=findDivisors(x);
        divisors.addAll(findDivisors(y));
        int ans=0,c=0;
        HashSet<Integer> remove=new HashSet<>();
        for(int i=0;i<n-1;i++){
            int a=sc.nextInt(),b=sc.nextInt();
            for(int div:divisors){
                if(remove.contains(div))
                    continue;
                if(a%div!=0&&b%div!=0) {
                    remove.add(div);
                    c++;
                }else
                    ans=div;
            }
            if(divisors.size()-c<=0){
                System.out.println(-1);
                return;
            }
        }
        System.out.println(ans);
     }

    public static <E> void print2D(E[][] arr) {
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                pw.println(arr[i][j]);
            }
        }
    }

    public static int digitSum(String s) {
        int toReturn = 0;
        for (int i = 0; i < s.length(); i++) toReturn += Integer.parseInt(s.charAt(i) + " ");
        return toReturn;
    }

    public static boolean isPrime(long n) {
        if (n <= 1)
            return false;
        if (n <= 3)
            return true;

        if (n % 2 == 0 || n % 3 == 0)
            return false;

        for (long i = 5; i * i <= n; i = i + 6)
            if (n % i == 0 || n % (i + 2) == 0)
                return false;
        return true;
    }

    public static long pow(long a, long pow) {
        return pow == 0 ? 1 : pow % 2 == 0 ? pow(a * a, pow >> 1) : a * pow(a * a, pow >> 1);
    }

    public static long sumNum(long a) {
        return a * (a + 1) / 2;
    }

    public static int gcd(int n1, int n2) {
        return n2 == 0 ? n1 : gcd(n2, n1 % n2);
    }

    public static long factorial(long a) {
        return a == 0 || a == 1 ? 1 : a * factorial(a - 1);
    }

    public static void sort(int arr[]) {
        shuffle(arr);
        Arrays.sort(arr);
    }

    public static void shuffle(int arr[]) {
        Random rnd = new Random();
        for (int i = arr.length - 1; i > 0; i--) {
            int index = rnd.nextInt(i + 1);
            int temp = arr[index];
            arr[index] = arr[i];
            arr[i] = temp;
        }
    }

    public static Double[] solveQuadratic(double a, double b, double c) {
        double result = (b * b) - 4.0 * a * c;
        double r1;
        if (result > 0.0) {
            r1 = ((double) (-b) + Math.pow(result, 0.5)) / (2.0 * a);
            double r2 = ((double) (-b) - Math.pow(result, 0.5)) / (2.0 * a);
            return new Double[]{r1, r2};
        } else if (result == 0.0) {
            r1 = (double) (-b) / (2.0 * a);
            return new Double[]{r1, r1};
        } else {
            return new Double[]{null, null};
        }
    }

    static class Scanner {
        StringTokenizer st;
        BufferedReader br;

        public Scanner(FileReader r) {
            br = new BufferedReader(r);
        }

        public Scanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

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

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

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

        public String nextLine() throws IOException {
            return br.readLine();
        }

        public double nextDouble() throws IOException {
            String x = next();
            StringBuilder sb = new StringBuilder("0");
            double res = 0, f = 1;
            boolean dec = false, neg = false;
            int start = 0;
            if (x.charAt(0) == '-') {
                neg = true;
                start++;
            }
            for (int i = start; i < x.length(); i++)
                if (x.charAt(i) == '.') {
                    res = Long.parseLong(sb.toString());
                    sb = new StringBuilder("0");
                    dec = true;
                } else {
                    sb.append(x.charAt(i));
                    if (dec)
                        f *= 10;
                }
            res += Long.parseLong(sb.toString()) / f;
            return res * (neg ? -1 : 1);
        }

        public boolean ready() throws IOException {
            return br.ready();
        }
    }

    static class pair<E1, E2> implements Comparable<pair> {
        E1 x;
        E2 y;

        pair(E1 x, E2 y) {
            this.x = x;
            this.y = y;
        }

        @Override
        public int compareTo(pair o) {
            return x.equals(o.x) ? (Integer) y - (Integer) o.y : (Integer) x - (Integer) o.x;
        }

        @Override
        public String toString() {
            return x + " " + y;
        }

        public double pointDis(pair p1) {
            return Math.sqrt(((Integer) y - (Integer) p1.y) * ((Integer) y - (Integer) p1.y) + ((Integer) x - (Integer) p1.x) * ((Integer) x - (Integer) p1.x));
        }
    }

}
