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.
/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Codechef
{   
	public static void main (String[] args) throws java.lang.Exception
	{  FastReader in = new FastReader(System.in);
        StringBuilder sb = new StringBuilder();
        int t=1;
        //t=in.nextInt();
        while(t>0){
            --t;
            int n = in.nextInt();
            int arr[][] = new int[n][2];
            for(int i=0;i<n;i++)
            {
                arr[i][0] = in.nextInt();
                arr[i][1] = in.nextInt();
            }
            int prev = -1;
            Arrays.sort(arr,(int l1[],int l2[])->{
               if(l1[0]!=l2[0]) 
               return Integer.compare(l1[0],l2[0]);
               else 
               return Integer.compare(l1[1],l2[1]);
            });
            for(int i=0;i<n;i++)
            {
                if(arr[i][1]>=prev)
                {
                    prev = arr[i][1];
                }
                else 
                prev = arr[i][0];
            }
            System.out.println(prev);
        }
	    
	}
	
    static int upper_bound(int arr[],int x){
	    int a=Arrays.binarySearch(arr,x);
	    if(a<0){
	        a*=(-1);
	    
	        return a-1; 
	    }
	    else{
	        
	        while(a<arr.length && arr[a]==x)
	           ++a;
	           return a;
	    }
	}
	static long gcd(long a ,long b)
	{
    if(a==0)
    return b;
    else return gcd(b%a,a);
    }
    
//------making a Fendwick tree ---//
	// creating a fendwick tree
	static long ftree[];
	static void buildFendwicktree(int arr[],int n)
	{
		ftree=new long[n+1];
		for(int i=0;i<n;i++)
			upftree(arr[i],i,n);
	}
	static void upftree(int value,int n,int i)
	{
		int index=i+1;
		while(index<=n)
		{
		  ftree[index]+=value;
		  index+=(index&(-index));  // adding last bit to the index 
		}
	}
	static long getSum(int index)
	{
		long sum=0;
		index+=1;
		while(index>0)
		{
			sum+=ftree[index];
			index-=(index&(-index)); // fliping last index of the tree; 
		}
		return sum;
	}
//------Fendwick tree ends ---------//
}


class sgmtree{
    int arr[];
    sgmtree(int input[],int n){
        arr=new int[100001];
        buildtree(input,1,0,n-1);
    }
    void buildtree(int input[],int si,int ss,int se){
        if(ss==se){
         arr[si]=input[ss];
         return;
        }
         int mid=(ss+se)/2;
         buildtree(input,2*si,ss,mid);
         buildtree(input,2*si+1,mid+1,se);
         arr[si]=Math.min(arr[2*si],arr[2*si+1]);
         
    }
    int query(int si,int ss,int se,int qs,int qe){
        if(qs>se  || qe<ss)
         return Integer.MAX_VALUE;
        
        if(ss>=qs && qe>=se)
        return arr[si];
        
        int mid=(ss+se)/2;
        int l=query(2*si,ss,mid,qs,qe);
        int r=query(2*si+1,mid+1,se,qs,qe);
        return Math.min(l,r);
    }
    void update(int input[],int index,int value){
        input[index]=value;
        updateutils(input,1,0,input.length-1,index);
    }
    void updateutils(int input[],int si,int ss,int se,int qi){
        if(ss==se){
            arr[si]=input[ss];
            return;
        }
        int mid=(ss+se)/2;
        if(qi<=mid)
        updateutils(input,2*si,ss,mid,qi);
        else
        updateutils(input,2*si+1,mid+1,se,qi);
        arr[si]=Math.min(arr[2*si],arr[2*si+1]);
    }
    
}
	
	/* This is for sorting first accorting to gain[1] if gain[1] is same the gain[0]
Arrays.sort(gain, (long[] l1, long[] l2) -> {
	        if(l1[1] != l2[1])return Long.compare(l2[1], l1[1]);//Sorting in non-increasing order of gain
	        return Long.compare(l1[0], l2[0]);//Choosing smallest bit among all bits having same gain
	    });
*/

class pair{
    int x,y;
    pair(int x,int y){
        this.x=x;
        this.y=y;
    }
}	
class CompareValue { 
  
    static void compare(pair arr[], int n) 
    { 
        Arrays.sort(arr, new Comparator<pair>() { 
        public int compare(pair p1, pair p2) 
            { 
                return p1.y - p2.y; 
            } 
        }); 
    } 
}
class CompareKey{
    static void compare(pair arr[],int n){
        Arrays.sort(arr,new Comparator<pair>(){
            public int compare(pair p1,pair p2)
            {
                return p2.x-p1.x;
            }
        });
    }
}
class FastReader {

    byte[] buf = new byte[2048];
    int index, total;
    InputStream in;

    FastReader(InputStream is) {
        in = is;
    }

    int scan() throws IOException {
        if (index >= total) {
            index = 0;
            total = in.read(buf);
            if (total <= 0) {
                return -1;
            }
        }
        return buf[index++];
    }

    String next() throws IOException {
        int c;
        for (c = scan(); c <= 32; c = scan()) ;
        StringBuilder sb = new StringBuilder();
        for (; c > 32; c = scan()) {
            sb.append((char) c);
        }
        return sb.toString();
    }

    String nextLine() throws IOException {
        int c;
        for (c = scan(); c <= 32; c = scan()) ;
        StringBuilder sb = new StringBuilder();
        for (; c != 10 && c != 13; c = scan()) {
            sb.append((char) c);
        }
        return sb.toString();
    }

    char nextChar() throws IOException {
        int c;
        for (c = scan(); c <= 32; c = scan()) ;
        return (char) c;
    }

    int nextInt() throws IOException {
        int c, val = 0;
        for (c = scan(); c <= 32; c = scan()) ;
        boolean neg = c == '-';
        if (c == '-' || c == '+') {
            c = scan();
        }
        for (; c >= '0' && c <= '9'; c = scan()) {
            val = (val << 3) + (val << 1) + (c & 15);
        }
        return neg ? -val : val;
    }

    long nextLong() throws IOException {
        int c;
        long val = 0;
        for (c = scan(); c <= 32; c = scan()) ;
        boolean neg = c == '-';
        if (c == '-' || c == '+') {
            c = scan();
        }
        for (; c >= '0' && c <= '9'; c = scan()) {
            val = (val << 3) + (val << 1) + (c & 15);
        }
        return neg ? -val : val;
    }
}	