Student Valera is an undergraduate student at the University. His end of term exams are approaching and he is to pass exactly n exams. Valera is a smart guy, so he will be able to pass any exam he takes on his first try. Besides, he can take several exams on one day, and in any order.

According to the schedule, a student can take the exam for the i-th subject on the day number ai. However, Valera has made an arrangement with each teacher and the teacher of the i-th subject allowed him to take an exam before the schedule time on day bi (bi < ai). Thus, Valera can take an exam for the i-th subject either on day ai, or on day bi. All the teachers put the record of the exam in the student's record book on the day of the actual exam and write down the date of the mark as number ai.

Valera believes that it would be rather strange if the entries in the record book did not go in the order of non-decreasing date. Therefore Valera asks you to help him. Find the minimum possible value of the day when Valera can take the final exam if he takes exams so that all the records in his record book go in the order of non-decreasing date.

Input

The first line contains a single positive integer n (1 ≤ n ≤ 5000) — the number of exams Valera will take.

Each of the next n lines contains two positive space-separated integers ai and bi (1 ≤ bi < ai ≤ 109) — the date of the exam in the schedule and the early date of passing the i-th exam, correspondingly.

Output

Print a single integer — the minimum possible number of the day when Valera can take the last exam if he takes all the exams so that all the records in his record book go in the order of non-decreasing date.

Examples

Input

3
5 2
3 1
4 2


Output

2


Input

3
6 1
5 2
4 3


Output

6

Note

In the first sample Valera first takes an exam in the second subject on the first day (the teacher writes down the schedule date that is 3). On the next day he takes an exam in the third subject (the teacher writes down the schedule date, 4), then he takes an exam in the first subject (the teacher writes down the mark with date 5). Thus, Valera takes the last exam on the second day and the dates will go in the non-decreasing order: 3, 4, 5.

In the second sample Valera first takes an exam in the third subject on the fourth day. Then he takes an exam in the second subject on the fifth day. After that on the sixth day Valera takes an exam in the first subject.

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

public class Level {

    public static DS.Scanner in = new DS.Scanner();
    public static DS.Print out = new DS.Print();

    public static double getDist(Point a, Point b) {
        return Math.sqrt((b.x - a.x) * (b.x - a.x) + (b.y - a.y) * (b.y - a.y));
    }

    public static boolean isInt(double dist) {
        int tst = (int) dist;
        double x = tst;
        if (x == dist) {
            return true;
        } else {
            return false;
        }
    }

    public static void main(String[] args) {
        ArrayList<Point> list = new ArrayList<Point>();
        int n = in.nextInt();
        for (int i = 0; i < n; i++) {
            list.add(new Point(in.nextInt(), in.nextInt()));
        }
        Collections.sort(list);
        int max = list.get(0).y;
        for (int i = 1; i < list.size(); i++) {
            Point p = list.get(i);
            if (p.y >= max) {
                max = Math.max(max, p.y);
            } else {
                max = Math.max(max, p.x);
            }
        }
        System.out.println(max);
    }

    public static class Algo {

        public static int lowerBound(ArrayList<Long> list, int length, long value) {
            int low = 0;
            int high = length;
            while (low < high) {
                final int mid = (low + high) / 2;
                if (value <= list.get(mid)) {
                    high = mid;
                } else {
                    low = mid + 1;
                }
            }
            return low;
        }

        public static int upperBound(ArrayList<Long> list, int length, long value) {
            int low = 0;
            int high = length;
            while (low < high) {
                final int mid = (low + high) / 2;
                if (value >= list.get(mid)) {
                    low = mid + 1;
                } else {
                    high = mid;
                }
            }
            return low;
        }

        public static void merge(int arr[], int l, int m, int r) {
            int n1 = m - l + 1;
            int n2 = r - m;

            int L[] = new int[n1];
            int R[] = new int[n2];

            for (int i = 0; i < n1; ++i) {
                L[i] = arr[l + i];
            }
            for (int j = 0; j < n2; ++j) {
                R[j] = arr[m + 1 + j];
            }

            int i = 0, j = 0;

            int k = l;
            while (i < n1 && j < n2) {
                if (L[i] <= R[j]) {
                    arr[k] = L[i];
                    i++;
                } else {
                    arr[k] = R[j];
                    j++;
                }
                k++;
            }

            while (i < n1) {
                arr[k] = L[i];
                i++;
                k++;
            }

            while (j < n2) {
                arr[k] = R[j];
                j++;
                k++;
            }
        }

        public static void sort(int arr[], int l, int r) {
            if (l < r) {
                int m = (l + r) / 2;

                sort(arr, l, m);
                sort(arr, m + 1, r);

                merge(arr, l, m, r);
            }
        }

        public static ArrayList<Integer> sieve(int n) {
            long sqr = (long) Math.sqrt(n);
            boolean[] isPrime = new boolean[n + 1];
            for (int i = 0; i <= n; i++) {
                isPrime[i] = true;
            }
            for (int i = 2; i <= sqr; i++) {
                if (isPrime[i]) {
                    for (int p = i * i; p <= n; p += i) {
                        isPrime[p] = false;
                    }
                }
            }
            ArrayList<Integer> list = new ArrayList<Integer>();
            for (int i = 0; i <= n; i++) {
                if (isPrime[i]) {
                    list.add(i);
                }
            }
            list.remove(0);
            list.remove(0);
            return list;
        }

        public static boolean isPrime(long n) {
            boolean res = true;
            List l = sieve((int) Math.sqrt(n));
            for (int i = 0; i < l.size(); i++) {
                int curPrime = (int) l.get(i);
                if (n % curPrime == 0) {
                    res = false;
                    break;
                }
            }
            return res;
        }

        public static ArrayList factorizatin(int n) {

            ArrayList<Integer> list = new ArrayList<Integer>();
            if (n == 1) {
                list.add(1);
                return list;
            } else if (n == 2) {
                list.add(2);
                return list;
            } else {
                if (isPrime(n)) {
                    System.out.println(-1);
                    return null;
                } else {
                    Iterator ptr = sieve((int) Math.sqrt(n)).iterator();
                    if (ptr.hasNext()) {
                        int cur = (int) ptr.next();
                        // System.out.println(cur);
                        while (n != 1) {
                            System.out.println(n);
                            while (n % cur == 0) {
                                list.add(cur);
                                n /= cur;
                            }
                            if (ptr.hasNext()) {
                                cur = (int) ptr.next();
                            }
                            //System.out.println(cur);
                        }
                    }
                    if (n > 2) {
                        list.add(n);
                    }
                }
                return list;
            }
        }

        public static long gcd(long a, long b) {
            if (b == 0) {
                return a;
            } else {
                return gcd(b, a % b);
            }
        }

        public static long lcm(long a, long b) {
            long ab = a * b;
            long gcd = gcd(a, b);
            return ab / gcd;
        }

        public static int bs(int[] z, int k) {
            int res = 0;
            int l = 0;
            int r = z.length - 1;
            int mid = (l + r) / 2;
            while (l <= r) {

                if (z[mid] == k) {
                    res = 1;
                    break;
                }
                if (z[mid] > k) {
                    r = mid - 1;
                } else {
                    l = mid + 1;
                }
                mid = (l + r) / 2;
            }
            return res;
        }

        public static void solve() {
            int n = Integer.parseInt(in.next());
            int target = Integer.parseInt(in.next());
            int[] z = new int[n];
            for (int i = 0; i < n; i++) {
                z[i] = Integer.parseInt(in.next());
            }
            Arrays.sort(z);
            int ptr1 = 0;
            int ptr2 = n - 1;
            int wind = z[ptr1] + z[ptr2];
            if (wind == target) {
                System.out.println(ptr1 + "-" + ptr2);
            } else {
                while (ptr1 < ptr2 && wind != target) {
                    if (wind > target) {
                        wind -= z[ptr2--];
                        wind += z[ptr2];
                    } else {
                        wind -= z[ptr1++];
                        wind += z[ptr1];
                    }
                }
                if ((ptr1 != 0 || ptr2 != n - 1) && ptr2 != ptr1) {
                    System.out.println(ptr1 + "-" + ptr2);
                } else {
                    System.out.println(-1);
                }
            }
        }

        public static void sliding() {
            int n = Integer.parseInt(in.next());
            int k = Integer.parseInt(in.next());
            int[] z = new int[n];
            for (int i = 0; i < n; i++) {
                z[i] = Integer.parseInt(in.next());
            }
            int wind = 0;
            for (int i = 0; i < k; i++) {
                wind += z[i];
            }
            int max = wind;
            for (int i = k; i < n; i++) {
                wind += z[i];
                wind -= z[i - k];
                max = Math.max(max, wind);
            }
            System.out.println(max);
        }

        public static ArrayList<Integer> dd(int n) {
            ArrayList<Integer> list = new ArrayList<Integer>();
            for (int i = 1; i * i <= n; i++) {
                if (n % i == 0) {
                    list.add(n / i);
                    list.add(i);
                }
            }

            return list;
        }
    }

    private static class DS {

        public static class Print {

            private final BufferedWriter bw;

            public Print() {
                this.bw = new BufferedWriter(new OutputStreamWriter(System.out));
            }

            public void print(Object object) throws IOException {
                bw.append(object + " ");
            }

            public void println(Object object) throws IOException {
                print(object);
                bw.append("\n");
            }

            public void close() throws IOException {
                bw.close();
            }
        }

        private static class Graph {

            int V = 0;
            ArrayList<Integer>[] list = null;

            public Graph(int v) {
                this.V = v + 1;
                this.list = new ArrayList[this.V];
                for (int i = 0; i < list.length; i++) {
                    list[i] = new ArrayList<Integer>();
                }
            }

            public void addEdge(int s, int v) {
                list[s].add(v);
                list[v].add(s);
            }

            public int count(int s, boolean[] v, int[] cmpOfNode, int cmp) {
                int count = 1;
                Queue<Integer> q = new LinkedList();
                q.add(s);
                v[s] = true;
                while (q.size() > 0) {
                    int cur = q.poll();
                    cmpOfNode[cur] = cmp;
                    v[cur] = true;
                    ArrayList<Integer> st = list[cur];
                    for (int val : st) {
                        if (!v[val]) {
                            q.add(val);
                            cmpOfNode[val] = cmp;
                            v[val] = true;
                            count++;
                        }
                    }
                }
                return count;
            }
        }

        private static class Stack {

            private int Size;
            Node top;
            Node last;

            Stack() {

                Size = 0;
                top = null;
                last = null;
            }

            public int size() {
                return this.Size;
            }

            public void push(Object item) {
                Node node = new Node();
                node.data = item;
                node.next = top;
                top = node;
                Size++;
            }

            public void pop() {
                if (top != null) {
                    top = top.next;
                }
                Size--;
            }

            public boolean isEmpty() {
                return top == null;
            }

            public Object getTop() {
                if (top != null) {
                    return top.data;
                } else {
                    return null;
                }
            }

            public void display() {
                if (top != null) {
                    Node temp = top;
                    while (temp != null) {
                        System.out.print(temp.data + " ");
                        temp = temp.next;
                    }
                    System.out.println();
                }
            }

            private class Node {

                Object data;
                Node next;
            }
        }

        private static class Scanner {

            BufferedReader br;
            StringTokenizer st;

            public Scanner() {
                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();
            }

            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;
            }

            BigInteger nextBigInteger() {
                return new BigInteger(next());
            }

        }
    }

    public static class Point implements Comparable<Point> {

        int x = 0;
        int y = 0;

        public Point(int x, int y) {
            this.x = x;
            this.y = y;
        }

        @Override
        public int compareTo(Point t) {
            if (this.x - t.x == 0) {
                int v = this.y - t.y;
                if (v == 0) {
                    return 0;
                } else if (this.y > t.y) {
                    return 1;
                } else {
                    return -1;
                }
            } else {
                return this.x - t.x;
            }
        }
    }
}
