When Xellos was doing a practice course in university, he once had to measure the intensity of an effect that slowly approached equilibrium. A good way to determine the equilibrium intensity would be choosing a sufficiently large number of consecutive data points that seems as constant as possible and taking their average. Of course, with the usual sizes of data, it's nothing challenging — but why not make a similar programming contest problem while we're at it?

You're given a sequence of n data points a1, ..., an. There aren't any big jumps between consecutive data points — for each 1 ≤ i < n, it's guaranteed that |ai + 1 - ai| ≤ 1.

A range [l, r] of data points is said to be almost constant if the difference between the largest and the smallest value in that range is at most 1. Formally, let M be the maximum and m the minimum value of ai for l ≤ i ≤ r; the range [l, r] is almost constant if M - m ≤ 1.

Find the length of the longest almost constant range.

Input

The first line of the input contains a single integer n (2 ≤ n ≤ 100 000) — the number of data points.

The second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 100 000).

Output

Print a single number — the maximum length of an almost constant range of the given sequence.

Examples

Input

5
1 2 3 3 2


Output

4


Input

11
5 4 5 5 6 7 8 8 8 7 6


Output

5

Note

In the first sample, the longest almost constant range is [2, 5]; its length (the number of data points in it) is 4.

In the second sample, there are three almost constant ranges of length 4: [1, 4], [6, 9] and [7, 10]; the only almost constant range of the maximum length 5 is [6, 10].
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.StringTokenizer;

public class B {
  FastScanner in;
  PrintWriter out;

  public void run() {
    try {
      in = new FastScanner(new InputStreamReader(System.in));
      out = new PrintWriter(System.out);
      solve();
      out.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  int n;
  int [] a;
  public void solve() throws IOException {
    n = in.nextInt();
    a = new int[n];
    for (int i=0; i<n; i++) {
      a[i] = in.nextInt();
    }
    
    if (n == 2) {
      out.println(2);
      return;
    }
    
    int start = 0;
    int pos = -1;
    int maxD = 0;
    for (int i=0; i<n-1; i++) {
      if (a[i] != a[i+1]) {
//        if (pos >=0)System.out.printf("a[%d]=%d, a[%d]=%d, pos=%d, a[pos]=%d, a[pos+1]=%d, start=%d, maxD=%d\n", i, a[i], i+1, a[i+1], pos, a[pos], a[pos+1], start, maxD);
        if (pos >=0 && ((a[i] > a[i+1] && a[pos] > a[pos+1]) || (a[i] < a[i+1] && a[pos] < a[pos+1])) ) {
//          System.out.printf("\tmaxD=%d vs %d\n", maxD, i-start+1);
          if (maxD < i - start + 1) {
            maxD = i - start + 1;
          }
          int j = i;
          while (j >= 0 && a[j] == a[i]) {
            j--;
          }
          start = j+1;
//          System.out.printf("\tnew maxD=%d, set start=%d\n", maxD, start);
        }
        pos = i;
      }
      if (i == n-2 && start != n-2) {
//        System.out.printf("\tmaxD=%d vs %d\n", maxD, i-start+1);
        if (maxD < i - start + 2) {
          maxD = i - start + 2;
        }
      }
    }
    out.println(maxD);
  }

  class FastScanner {
    BufferedReader br;
    StringTokenizer st;

    FastScanner(InputStreamReader in) {
      br = new BufferedReader(in);
    }

    String nextLine() {
      String str = null;
      try {
        str = br.readLine();
      } catch (IOException e) {
        e.printStackTrace();
      }

      return str;
    }

    String next() {
      while (st == null || !st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      return st.nextToken();
    }

    int nextInt() {
      return Integer.parseInt(next());
    }
  }

  public static void main(String[] arg) {
    B o = new B();
    o.run();
//    System.out.println('Z' - 55);
  }

}