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.


/**
 * Created by sky on 20/8/18.
 * www.github.com/aakashjaiswal1
 * aakashjaiswal@hotmail.co.in
 * aakashjaiswal.in@gmail.com
 * people die if they are killed
 */
/**
 * Created by sky on 19/8/18.
 * www.github.com/aakashjaiswal1
 * aakashjaiswal@hotmail.co.in
 * aakashjaiswal.in@gmail.com
 * people die if they are killed
 */
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class default_jnjt {
    public static void main(String[] args) {
        in = new FastReader();
        int N=ni();
        Set<Integer> set=getPrime(ni());
        set.addAll(getPrime(ni()));
        int[][] storer=new int[N-1][2];
        for (int i=0;i<N-1;i++){
            storer[i][0]=ni();
            storer[i][1]=ni();
        }
       ml: for (int prime:set){
            for (int i=0;i<storer.length;i++){
                int ele1=storer[i][0];
                int ele2=storer[i][1];
                if (!(ele1%prime==0||ele2%prime==0)){
                    continue ml;
                }
            }
           System.out.println(prime);
            return;
        }
        System.out.println("-1");
    }
    public static long binarySearch(long low, long high) {
        while (high - low > 1) {
            long mid = (high - low)/2 + low;
            //System.out.println(mid);
            if (works(mid)) {
                high = mid;
            } else {
                low = mid;
            }
        }
        return (works(low) ? low : high);
    }

    private static Set<Integer> getPrime(int value) {

        Set<Integer> set = new HashSet<>();
        for (int i = 2;i * i <= value;i ++) {
            if (value % i == 0) {
                while (value % i == 0) {
                    value /= i;
                }
                set.add(i);
            }
        }
        if (value > 1) {
            set.add(value);
        }
        return set;

    }
    static class Graph{
        ArrayList<Integer> al_array[];
        int nodes;
        Graph(int no){
            this.nodes=no;
            this.al_array=new ArrayList[no];
            for (int i=0;i<no;i++){
                al_array[i]=new ArrayList<>();
            }
        }
        void addDir(int i,int j){
            this.al_array[i].add(j);
        }
        void addUndir(int i,int j){
            this.al_array[i].add(j);
            this.al_array[j].add(i);
        }
        Graph compliment(){
            Graph com=new Graph(this.nodes);
            for (int i=0;i<this.nodes;i++){
                ArrayList<Integer> al=this.al_array[i];
                for (int j=0;j<al.size();j++){
                    int node=al.get(j);
                    com.addDir(node,i);
                }
            }
            return com;
        }

    }
    static void  printLN2DArray(int[][] arr){
        StringBuilder sb=new StringBuilder();
        for (int i=0;i<arr.length;i++){
            for (int j=0;j<arr[i].length;j++){
                sb.append(arr[i][j]).append(" ");
            }
            sb.append("\n");
        }
        System.out.println(sb.toString());
    }
    static long fast_exp_with_mod(long base, long exp) {
        long MOD=1000000000+7;
        long res=1;
        while(exp>0) {
            if(exp%2==1) res=(res*base)%MOD;
            base=(base*base)%MOD;
            exp/=2;
        }
        return res%MOD;
    }
    public static long gcd(long a, long b)
    {
        if (a == 0)
            return b;
        return gcd(b%a, a);
    }
    static class my_no{
        long num;
        long denom;

        @Override
        public String toString() {
            if (denom<0){
                this.num=-this.num;
                this.denom=-this.denom;
            }
            if (num==0)return "0";
            return (num+"/"+denom);
        }

        my_no(int no){
            this.num=no;
            this.denom=1;
        }
        my_no(long num,long denom){
            this.num=num;
            this.denom=denom;
        }

        my_no multiply(my_no obj){
            long num1=obj.num;
            long denom1=obj.denom;
            long n=num1*num;
            long d=denom1*denom;
            long gcd=gcd(n,d);
            n/=gcd;
            d/=gcd;
            return new my_no(n,d);

        }
//        my_no multiply(my_no obj){
//            long num1=obj.num;
//            long denom1=obj.denom;
//            long num2=this.num;
//            long denom2=this.denom;
//
//        }

        my_no multiply(int no){
            long n=num*no;
            long d=denom;
            long gcd=gcd(n,d);
            n/=gcd;
            d/=gcd;
            return new my_no(n,d);

        }
    }
    static void memset(int[][] arr,int val){
        for (int i=0;i<arr.length;i++){
            for (int j=0;j<arr[i].length;j++){
                arr[i][j]=val;
            }
        }
    }
    static void memset(int[] arr,int val){
        for (int i=0;i<arr.length;i++){
            arr[i]=val;
        }
    }


    static void memset(long[][] arr,long val){
        for (int i=0;i<arr.length;i++){
            for (int j=0;j<arr[i].length;j++){
                arr[i][j]=val;
            }
        }
    }
    static void memset(long[] arr,long val){
        for (int i=0;i<arr.length;i++){
            arr[i]=val;
        }
    }
    static private boolean works(long test){
        return true;
    }


    static void reverse(char[] arr ,int i,int j){
        if (i==j)
            return;
        while (i<j){
            char temp=arr[i];
            arr[i]=arr[j];
            arr[j]=temp;
            ++i;
            --j;
        }
    }
    static int[]  takeIntegerArrayInput(int no){
        int[] arr=new int[no];
        for (int i=0;i<no;++i){
            arr[i]=ni();
        }
        return arr;
    }
    static long fast_Multiply(long no , long pow){
        long result=1;
        while (pow>0){
            if ((pow&1)==1){
                result=result*no;
            }
            no=no*no;
            pow>>=1;
        }
        return result;
    }

    static long[]  takeLongArrayInput(int no){
        long[] arr=new long[no];
        for (int i=0;i<no;++i){
            arr[i]=ni();
        }
        return arr;
    }
    static final long MOD = (long)1e9+7;
    static FastReader in;


    static void p(Object o){
        System.out.print(o);
    }

    static void pn(Object o){
        System.out.println(o);
    }

    static String n(){
        return in.next();
    }

    static String nln(){
        return in.nextLine();
    }

    static int ni(){
        return Integer.parseInt(in.next());
    }

    static int[] ia(int N){
        int[] a = new int[N];
        for(int i = 0; i<N; i++)a[i] = ni();
        return a;
    }

    static long[] la(int N){
        long[] a = new long[N];
        for(int i = 0; i<N; i++)a[i] = nl();
        return a;
    }

    static long nl(){
        return Long.parseLong(in.next());
    }

    static double nd(){
        return Double.parseDouble(in.next());
    }

    static class FastReader{
        BufferedReader br;
        StringTokenizer st;
        public FastReader(){
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next(){
            while (st == null || !st.hasMoreElements()){
                try{
                    st = new StringTokenizer(br.readLine());
                }catch (IOException e){
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        String nextLine(){
            String str = "";
            try{
                str = br.readLine();
            }catch (IOException e){
                e.printStackTrace();
            }
            return str;
        }
    }
    static void println(String[] arr){
        for (int i=0;i<arr.length;++i){
            System.out.println(arr[i]);
        }
    }

}

