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.*;
import java.util.ArrayList;
import java.util.StringTokenizer;

public class I_O {
    
    public static void main(String args[])throws IOException {
        
    	//CODE HERE	
    	int n = in.nextInt();
		int arr[][] = new int[n][2];
		int min = Integer.MAX_VALUE, ind = 0;
		for(int i=0; i<n; i++) {
			arr[i][0] = in.nextInt();
			arr[i][1] = in.nextInt();
			int m = Math.min(arr[i][0], arr[i][1]);
			if(m<min) {
				min=m; ind = i;
			}
		}
		
		int a = arr[ind][0], b = arr[ind][1];
		int aa[] = new int[32];
		int bb[] = new int[32];
		int q = 0;
		if(a%2==0) aa[q++]=2;
		while(a%2==0) a/=2;
		for(int i=3; i<=Math.sqrt(a); i+=2) {
			if(a%i==0) {
				aa[q++] = i;
				while(a%i==0) a/=i;
			}
		} if(a>0) aa[q++] = a;
		/*for(int i=2; i<=Math.sqrt(a); i++) {
			if(a%i==0) {
				if(i == a/i) aa[q++] = i;
				else {
					aa[q++] = i;
					aa[q++] = a/i;
				} a/=i;
			}
		} aa[q++] = a;*/
		
		q = 0;
		if(b%2==0) bb[q++]=2;
		while(b%2==0) b/=2;
		for(int i=3; i<=Math.sqrt(b); i+=2) {
			if(b%i==0) {
				bb[q++] = i;
				while(b%i==0) b/=i;
			}
		} if(b>0) bb[q++] = b;
		/*for(int i=2; i<=Math.sqrt(b); i++) {
			if(b%i==0) {
				if(i == b/i) bb[q++] = i;
				else {
					bb[q++] = i;
					bb[q++] = b/i;
				} b/=i;
			} 
		} bb[q++] = b;*/
		int cnt = 0, ans = 0;
		for(int i=0; i<32; i++) {
			int curr = aa[i]; if(curr<2) continue;
			cnt = 0;
			for(int j=0; j<n; j++) {
				if(arr[j][0]%curr==0||arr[j][1]%curr==0) cnt++;
			}
			if(cnt==n) {
				ans = curr; break;
			}
		}
		if(ans!=0) out.print(ans+"\n");
		
		else {
			cnt = 0;
			for(int i=0; i<32; i++) {
				int curr = bb[i]; if(curr<2) continue;
				cnt = 0;
				for(int j=0; j<n; j++) {
					if(arr[j][0]%curr==0||arr[j][1]%curr==0) cnt++;
				}
				if(cnt==n) {
					ans = curr; break;
				}
			}
			if(ans!=0) out.print(ans+"\n");
			else out.print(-1+"\n");
		}
    	
    	out.flush();
    	out.close();
    }

    // Fast I/O
    static BR in = new BR();
	static Reader br = new Reader();	
    static OutputWriter out = new OutputWriter(System.out);
    
    static class BR {
 		BufferedReader br; StringTokenizer st;
 		public BR() {
 			br = new BufferedReader(new InputStreamReader(System.in));
 		}
 		int nextInt() {
 			return Integer.parseInt(next());
 		}
 		long nextLong() {
 			return Long.parseLong(next());
 		} 
 		double nextDouble() {
 			return Double.parseDouble(next()); 
 		}
 		String nextLine() {
 			String str = "";
 			try {
 				str=br.readLine();
 				}
 			catch (IOException e) {
 				e.printStackTrace();
 				}
 			return str;
 		}
 		String next() {
 			while(st==null||!st.hasMoreElements()) {
 				try {
 					st=new StringTokenizer(br.readLine());
 					}
 				catch(IOException e) {
 					e.printStackTrace();
 					}
 				}
 			return st.nextToken();
 		}
 	}
    
    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];
            int cnt = 0, c;
            while ((c = read()) != -1) {
                if (c == '\n')
                    break;
                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();
        }
    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0)
                    writer.print(' ');
                writer.print(objects[i]);
            }
        }

        public void close() {
            writer.close();
        }

        public void flush() {
            writer.flush();
        }

    }

    //
}