There are N integers X_1, X_2, \cdots, X_N, and we know that A_i \leq X_i \leq B_i. Find the number of different values that the median of X_1, X_2, \cdots, X_N can take.

Constraints

* 2 \leq N \leq 2 \times 10^5
* 1 \leq A_i \leq B_i \leq 10^9
* All values in input are integers.

Input

Input is given from Standard Input in the following format:


N
A_1 B_1
A_2 B_2
:
A_N B_N


Output

Print the answer.

Examples

Input

2
1 2
2 3


Output

3


Input

3
100 100
10 10000
1 1000000000


Output

9991
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.NoSuchElementException;

	
public class Main{
	
	public static void main(String[] args) {
		new Main().run();
	}
	
	final long MOD=998244353;

	long pow(long a,long n) {
		return n!=0?pow(a*a%MOD,n/2)*(n%2==1?a:1)%MOD:1;
	}
	
	long inv(long a) {
		return pow(a,MOD-2);
	}
	
	// n%2==1とする
	long max1(int N,long[] A,long[] B) {
		ArrayList<Long> list=new ArrayList<>();
		for (long v:B) list.add(v);
		Collections.sort(list);
		return list.get((N-1)/2);
	}
	
	// n%2==1とする
	long min1(int N,long[] A,long[] B) {
		ArrayList<Long> list=new ArrayList<>();
		for (long v:A) list.add(v);
		Collections.sort(list);
		return list.get((N-1)/2);
	}
	
	// n%2==0とする
	long max0(int N,long[] A,long[] B) {
		ArrayList<Long> list=new ArrayList<>();
		for (long v:B) list.add(v);
		Collections.sort(list);
		return list.get(N/2)+list.get(N/2-1);
	}
	
	// n%2==0とする
	long min0(int N,long[] A,long[] B) {
		ArrayList<Long> list=new ArrayList<>();
		for (long v:A) list.add(v);
		Collections.sort(list);
		return list.get(N/2)+list.get(N/2-1);
	}

	void run() {
		FastScanner sc=new FastScanner();
		int N=sc.nextInt();
		long[] A=new long[N];
		long[] B=new long[N];
		for (int i=0;i<N;++i) {
			A[i]=sc.nextLong();
			B[i]=sc.nextLong();
		}
		if (N%2==1) {
			System.out.println(max1(N,A,B)-min1(N,A,B)+1);
		} else {
			System.out.println(max0(N,A,B)-min0(N,A,B)+1);
		}
	}
	
	void tr(Object...objects) {System.out.println(Arrays.deepToString(objects));}
}

class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    
    public double nextDouble() { return Double.parseDouble(next());}
}
