import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] types = new int[n];
        int i = 0; 
        int j=0;
        int m = 0;
        
        int minValue = 3;
        int maxValue = 0;
        for(int types_i=0; types_i < n; types_i++){
            types[types_i] = in.nextInt(); 
            
            //j = types[0];         
            //System.out.println(+j);
           
            if (types[types_i]==j)
            {              
               ++m; 
               i=types[types_i];
            } else {
              j = types[types_i];  
            }            
        }
            System.out.println(m);
         if (m>0)
            System.out.println(i);
        // your code goes here
    }
}