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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.TreeMap;
import java.util.InputMismatchException;
import java.io.IOException;
import java.util.Comparator;
import java.util.ArrayList;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author Puneet    //FastRead class is taken from different online Sources
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastInput in = new FastInput(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        TreeMap<Integer, Integer> treeMap = new TreeMap<>();

        public void solve(int testNumber, FastInput in, PrintWriter out) {

            int n = in.ni();

            ArrayList<Pair> ar = new ArrayList<>();

            for (int i = 0; i < n; i++) {
                ar.add(new Pair(in.ni(), in.ni()));
            }

            ar.sort(Comparator.comparingInt(p -> p.f));

            primefact(ar.get(0).f);
            tadd(ar.get(0).f);
            primefact(ar.get(0).s);
            tadd(ar.get(0).s);

            boolean isdivide = true;
            int ans = -1;

            //    out.print(treeMap);

            for (int i : treeMap.keySet()) {

                isdivide = true;

                for (int j = 1; j < n; j++) {
                    if (ar.get(j).f % i != 0 && ar.get(j).s % i != 0) {
                        isdivide = false;
                        break;
                    }
                }

                if (isdivide) {
                    ans = i;
                    break;
                }

            }

            out.println(ans);

        }

        private void primefact(int a) {


            for (int i = 2; i <= Math.sqrt(a); i++) {

                if (a % i == 0) {
                    tadd(i);
                    while (a % i == 0) {
                        a /= i;
                    }
                }

                if (a > 2)
                    tadd(a);
            }
        }

        public void tadd(int x) {
            if (treeMap.containsKey(x))
                treeMap.put(x, treeMap.get(x) + 1);
            else
                treeMap.put(x, 1);
        }

        class Pair {
            int f;
            int s;

            public Pair(int f, int s) {
                this.f = f;
                this.s = s;
            }

        }

    }

    static class FastInput {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private FastInput.SpaceCharFilter filter;

        public FastInput(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int ni() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
}