/* package whatever; // 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. */
class Ideone
{
{
// your code goes here
Scanner sc
= new Scanner
(System.
in); int n = sc.nextInt();
long[] arr = new long[n];
for(int i =0;i<n;i++){
arr[i] = sc.nextLong();
}
long[] diff = new long[n];
for(int i = 1;i<n;i++){
diff[i] = arr[i]-arr[i-1];
//out.println(diff[i]);
}
int l = 0,mLen = 1;
long lastseen = 0;
for(int i =1;i<n;i++){
if(Math.
abs(diff
[i
]) <= 1){ if(diff[i] == lastseen && diff[i]!= 0){
l = i-1;
lastseen = diff[i];
// out.println("CASE 1");
// out.println(l);
}
else if(diff[i] != lastseen || (diff[i] == 0)){
if(i-l+1 > mLen){
mLen = i-l+1;
}
if(diff[i]!=0){
lastseen = diff[i];
}
// out.println("CASE 2");
// out.println(diff[i]);
}
}
else{
l = i-1;
}
// out.println(l);
}
out.println(mLen);
}
}
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