Problem: 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.

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
public class d {
    public static void main(String[] args) throws IOException {
        //Scanner s = new Scanner(System.in);
        BufferedReader s=new BufferedReader(new InputStreamReader(System.in));
        //       String[] st=s.readLine().trim().split("\\s+");
        //      a=Integer.parseInt(st[i]);
        //  String[] st1=s.readLine().trim().split("\\s+");
        StringBuilder sb = new StringBuilder();
        StringBuilder sb1 = new StringBuilder();
        String[] st1=s.readLine().trim().split("\\s+");
        int n=Integer.parseInt(st1[0]);
        String[] st2=s.readLine().trim().split("\\s+");
        long a=Integer.parseInt(st2[0]);
        long b=Integer.parseInt(st2[1]);
        HashMap<Long,Integer> h=new HashMap<>();
        ArrayList<Long> l=new ArrayList<>();

        for(long i=1;i<=Math.sqrt(a);i++){
            if(a%i==0){
               if(i!=1){
                   if(isPrime((int)i))
                   { l.add(i);
                h.put(i,1);}}
            if(i!=a/i){
                   if(isPrime((int)a/(int)i)){
                l.add(a/i);
                h.put(a/i,1);}
            }

            }
        }
        for(long i=1;i<=Math.sqrt(b);i++){
            if(b%i==0){
          if(!h.containsKey(i)&&i!=1){
              if(isPrime((int)i)){
                  l.add(i);
                h.put(i,1);}}
            if(i!=b/i){
                if(!h.containsKey(b/i)) {
                    if (isPrime((int) b / (int) i)) {

                        l.add(b / i);
                        h.put(b / i, 1);
                    }
                }}            }}

        for(int i=0;i<n-1;i++){
            String[] st3=s.readLine().trim().split("\\s+");
            long x=Integer.parseInt(st3[0]);
            long y=Integer.parseInt(st3[1]);
            for(long j:l){
                if(x%j!=0&&y%j!=0) {
                    h.put(j,0);
                }
            }
        }int flag=0;
        for(long j:l){
            if(h.get(j)==1){
                System.out.println(j);
                System.exit(0);
            }
        }
        System.out.println(-1);
    }
    static int[] vis;
    public static int countSetBits(int n)
    {
        return (BitsSetTable256[n & 0xff]
                + BitsSetTable256[(n >> 8) & 0xff]
                + BitsSetTable256[(n >> 16) & 0xff]
                + BitsSetTable256[n >> 24]);
    }
    static int[] BitsSetTable256 ;
    public static void initialize(int n)
    {
        BitsSetTable256[0] = 0;
        for (int i = 0; i <=Math.pow(2,n); i++) {
            BitsSetTable256[i] = (i & 1) + BitsSetTable256[i / 2];
        }
    }
    static HashMap<Integer,Integer>[] val;//static int[] vis;static int y;
    static boolean dfs(int x ,int i,ArrayList<Integer>[] adj){
      vis[i]=1;
     // if(x==1) System.out.print(i+" ");
      if(adj[i]==null) return false;
      for(int j:adj[i]){
        //  if(x==1) System.out.print(j+" ");
          if(j==x) return true;
          if(vis[j]==0) return dfs(x,j,adj);
      }return false;
    }

    static  void computeLPSArray(String pat, int M, int lps[]) {
        int len = 0;
        int i = 1;
        lps[0] = 0;
        while (i < M) {
            if (pat.charAt(i) == pat.charAt(len)) {
                len++;
                lps[i] = len;
                i++;
            }
            else
            {
                if (len != 0) {
                    len = lps[len - 1];
                }
                else
                {
                    lps[i] = len;
                    i++;
                }
            }
        }
    }
    static boolean isPrime(int n) {
        if (n <= 1) return false;
        if (n <= 3) return true;

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

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

        return true;
    }
    static long powerwithmod(long  x, long y, int p) {
        long  res = 1;
        x = x % p;
        while (y > 0) {
            if ((y & 1) == 1)
                res = (res * x) % p;
            y = y >> 1;
            x = (x * x) % p;
        }
        return res;
    }
    static long  powerwithoutmod(long x, int y) {
        long  temp;
        if( y == 0)
            return 1;
        temp = powerwithoutmod(x, y/2);
        if (y%2 == 0)
            return temp*temp;
        else
        {
            if(y > 0)
                return x * temp * temp;
            else
                return (temp * temp) / x;
        }
    }
    static void fracion(double x) {
        String a = "" + x;
        String spilts[] = a.split("\\."); // split using decimal
        int b = spilts[1].length(); // find the decimal length
        int denominator = (int) Math.pow(10, b); // calculate the denominator
        int numerator = (int) (x * denominator); // calculate the nerumrator Ex
        // 1.2*10 = 12
        int gcd = (int) gcd((long) numerator, denominator); // Find the greatest common
        // divisor bw them
        String fraction = "" + numerator / gcd + "/" + denominator / gcd;
        // System.out.println((denominator/gcd));
        long x1 = modInverse(denominator / gcd, 998244353);
        //  System.out.println(x1);
        System.out.println((((numerator / gcd) % 998244353 * (x1 % 998244353)) % 998244353));
    }
    static int bfs(int i1, ArrayList<Integer>[] h, int[] vis, int n,int val1) {
        Queue<Integer> q = new LinkedList<Integer>();
        q.add(i1);Queue<Integer> aq=new LinkedList<Integer>();
        aq.add(0);
        while(!q.isEmpty()){
            int i=q.poll();
            int val=aq.poll();
            if(i==n){
                return val;
            }
            if(h[i]!=null){
                for(Integer j:h[i]){
                    if(vis[j]==0){
                        q.add(j);vis[j]=1;
                        aq.add(val+1);}
                }
            }
        }return -1;
    }
    static long gcd(long a, long b) {
        if (b == 0)
            return a;
        return gcd(b, a % b);
    }
    static long modInverse(long a, int m)
    {
        return (powerwithmod(a, m - 2, m));
    }
    static int MAXN=100001;
    static int[] spf=new int[MAXN];
    static void sieve() {
        spf[1] = 1;
        for (int i=2; i<MAXN; i++)
            spf[i] = i;
        for (int i=4; i<MAXN; i+=2)
            spf[i] = 2;
        for (int i=3; i*i<MAXN; i++)
        {
            if (spf[i] == i)
            {
                for (int j=i*i; j<MAXN; j+=i)

                    if (spf[j]==j)
                        spf[j] = i;
            }
        }
    }
    static ArrayList<Integer> getFactorizationUsingSeive(int x) {
        ArrayList<Integer> ret = new ArrayList<Integer>();
        while (x != 1)
        {
            ret.add(spf[x]);
            x = x / spf[x];
        }
        return ret;
    }
   /*static long[] fac = new long[MAXN+1];
     static void calculatefac(int mod){
        for (int i = 1 ;i <= MAXN; i++)
            fac[i] = fac[i-1] * i % mod;
     }
      static long nCrModPFermat(int n, int r, int mod) {
         if (r == 0)
            return 1;
        fac[0] = 1;
        return (fac[n]* modInverse(fac[r], mod)
                % mod * modInverse(fac[n-r], mod)
                                    % mod) % mod;
    } */}
class Student {
    long  l;long r;int x;
    public Student(long l, long r) {
        this.l = l;
        this.r = r;this.x=x;
    }

    public String toString()
    {
        return this.l+" ";
    }
}
class Sortbyroll implements Comparator<Student>
{

    public int compare(Student a, Student b){
      if(a.l<b.l) return -1;
      else if(a.l==b.l){
          if(a.r==b.r){
              return 0;
          }
          if(a.r<b.r) return -1;
          return 1;}
      return 1;  }
}