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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {
    static PrintWriter out;
    static CF_Reader in;

    public static void main(String[] args) throws IOException {
        out = new PrintWriter(new OutputStreamWriter(System.out));
        in = new CF_Reader();

        int n = in.intNext();
        int[] lows = new int[n];
        int[] highs = new int[n];
        for (int i = 0; i < n; i++) {
            lows[i] = in.intNext();
            highs[i] = in.intNext();
        }
        Arrays.sort(lows);
        Arrays.sort(highs);
        int mid = n/2;
        int ans;
        if (n % 2 == 1) {
            ans = highs[mid] - lows[mid] + 1;
        } else {
            ans = (highs[mid - 1] + highs[mid]) - (lows[mid - 1] + lows[mid]) + 1;
        }
        out.println(ans);

        out.close();
    }


    static class CF_Reader {
        BufferedReader br;
        StringTokenizer st;

        public CF_Reader() throws IOException {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine().trim());
            return st.nextToken();
        }

        long longNext() throws IOException {
            return Long.parseLong(next());
        }

        int intNext() throws IOException {
            return Integer.parseInt(next());
        }

        double doubleNext() throws IOException {
            return Double.parseDouble(next());
        }

        char charNext() throws IOException {
            return next().charAt(0);
        }

        public int[] nextIntArray(final int n) throws IOException {
            final int[] a = new int[n];
            for (int i = 0; i < n; i++)
                a[i] = intNext();
            return a;
        }

        public long[] nextLongArray(final int n) throws IOException {
            final long[] a = new long[n];
            for (int i = 0; i < n; i++)
                a[i] = longNext();
            return a;
        }

        String line() throws IOException {
            return br.readLine().trim();
        }
    }
}


