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.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;

public class ApproximatingAConstantRange {

    private static Reader in;
    private static PrintWriter out;
    
    public static void main(String[] args) throws IOException {

        in = new Reader();
        out = new PrintWriter (System.out, true);
        
        int n = in.nextInt();
        int arr[] = new int[n+1];
        int dp[][] = new int[n+1][2];
        
        arr[1] = in.nextInt();
        dp[1][0] = 1;
        dp[1][1] = 1;
        for (int i = 2; i <= n; i++) {
            arr[i] = in.nextInt();
            if (arr[i] == arr[i-1]) {
                dp[i][0] += dp[i-1][0] + 1;
                dp[i][1] += dp[i-1][1] + 1;
            } else if(arr[i] > arr[i-1]) {
                dp[i][1] += dp[i-1][0] + 1;
                dp[i][0] = 1;
            } else {
                dp[i][0] += dp[i-1][1] + 1;
                dp[i][1] = 1;
            }
            //out.println(dp[i][0] + "" + dp[i][1]);
        }
        int result = 0;
        for (int i = 1; i <= n; i++)
            result = Math.max(result, Math.max(dp[i][0], dp[i][1]));
        out.println(result);
        out.close();
        in.close();
    }

    static class Reader {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;
        public Reader(){
            din=new DataInputStream(System.in);
            buffer=new byte[BUFFER_SIZE];
            bufferPointer=bytesRead=0;
        }

        public Reader(String file_name) throws IOException{
            din=new DataInputStream(new FileInputStream(file_name));
            buffer=new byte[BUFFER_SIZE];
            bufferPointer=bytesRead=0;
        }

        public String readLine() throws IOException{
            byte[] buf=new byte[64]; // line length
            int cnt=0,c;
            while((c=read())!=-1){
                if(c=='\n')break;
                buf[cnt++]=(byte)c;
            }
            return new String(buf,0,cnt);
        }

        public int nextInt() throws IOException{
            int ret=0;byte c=read();
            while(c<=' ')c=read();
            boolean neg=(c=='-');
            if(neg)c=read();
            do{ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');
            if(neg)return -ret;
            return ret;
        } 

        public long nextLong() throws IOException{
            long ret=0;byte c=read();
            while(c<=' ')c=read();
            boolean neg=(c=='-');
            if(neg)c=read();
            do{ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');
            if(neg)return -ret;
            return ret;
        }

        public double nextDouble() throws IOException{
            double ret=0,div=1;byte c=read();
            while(c<=' ')c=read();
            boolean neg=(c=='-');
            if(neg)c = read();
            do {ret=ret*10+c-'0';}while((c=read())>='0'&&c<='9');
            if(c=='.')while((c=read())>='0'&&c<='9')
                ret+=(c-'0')/(div*=10);
            if(neg)return -ret;
            return ret;
        }
        
        public char nextChar() throws IOException{
            byte c=read();
            while(c<=' ')c=read();
            return (char)c;
        }
        
        private void fillBuffer() throws IOException{
            bytesRead=din.read(buffer,bufferPointer=0,BUFFER_SIZE);
            if(bytesRead==-1)buffer[0]=-1;
        }
        
        private byte read() throws IOException{
            if(bufferPointer==bytesRead)fillBuffer();
            return buffer[bufferPointer++];
        }
        
        public void close() throws IOException{
            if(din==null) return;
            din.close();
        }
    }
}