Problem: Nikolay got a string s of even length n, which consists only of lowercase Latin letters 'a' and 'b'. Its positions are numbered from 1 to n.

He wants to modify his string so that every its prefix of even length has an equal amount of letters 'a' and 'b'. To achieve that, Nikolay can perform the following operation arbitrary number of times (possibly, zero): choose some position in his string and replace the letter on this position with the other letter (i.e. replace 'a' with 'b' or replace 'b' with 'a'). Nikolay can use no letters except 'a' and 'b'.

The prefix of string s of length l (1 ≤ l ≤ n) is a string s[1..l].

For example, for the string s="abba" there are two prefixes of the even length. The first is s[1...2]="ab" and the second s[1...4]="abba". Both of them have the same number of 'a' and 'b'.

Your task is to calculate the minimum number of operations Nikolay has to perform with the string s to modify it so that every its prefix of even length has an equal amount of letters 'a' and 'b'.

Input

The first line of the input contains one even integer n (2 ≤ n ≤ 2⋅10^{5}) — the length of string s.

The second line of the input contains the string s of length n, which consists only of lowercase Latin letters 'a' and 'b'.

Output

In the first line print the minimum number of operations Nikolay has to perform with the string s to modify it so that every its prefix of even length has an equal amount of letters 'a' and 'b'.

In the second line print the string Nikolay obtains after applying all the operations. If there are multiple answers, you can print any of them.

Examples

Input


4
bbbb


Output


2
abba


Input


6
ababab


Output


0
ababab


Input


2
aa


Output


1
ba

Note

In the first example Nikolay has to perform two operations. For example, he can replace the first 'b' with 'a' and the last 'b' with 'a'. 

In the second example Nikolay doesn't need to do anything because each prefix of an even length of the initial string already contains an equal amount of letters 'a' and 'b'.

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;


public class hello2
 {  
	static class FastReader 
       { 
           BufferedReader br; 
           StringTokenizer st; 
     
           public FastReader() 
           { 
               br = new BufferedReader(new
                        InputStreamReader(System.in)); 
           } 
     
           String next() 
           { 
               while (st == null || !st.hasMoreElements()) 
               { 
                   try
                   { 
                       st = new StringTokenizer(br.readLine()); 
                   } 
                   catch (IOException  e) 
                   { 
                       e.printStackTrace(); 
                   } 
               } 
               return st.nextToken(); 
           } 
     
           int nextInt() 
           { 
               return Integer.parseInt(next()); 
           } 
     
           long nextLong() 
           { 
               return Long.parseLong(next()); 
           } 
     
           double nextDouble() 
           { 
               return Double.parseDouble(next()); 
           } 
     
           String nextLine() 
           { 
               String str = ""; 
               try
               { 
                   str = br.readLine(); 
               } 
               catch (IOException e) 
               { 
                   e.printStackTrace(); 
               } 
               return str; 
           } 
         
       }
    
    static String sum (String s)
    {
        String s1 = ""; 
        
        if(s.contains("a"))
            s1+="a";
        if(s.contains("e"))
            s1+="e";
        if(s.contains("i"))
            s1+="i";
        if(s.contains("o"))
            s1+="o";
        if(s.contains("u"))
            s1+="u";
        
            return s1;
            
        
    }
    

    public static HashMap<String, Integer> sortByValue(HashMap<String, Integer> hm) 
    { 
        // Create a list from elements of HashMap 
        List<Map.Entry<String, Integer> > list = 
               new LinkedList<Map.Entry<String, Integer> >(hm.entrySet()); 
  
        // Sort the list 
        Collections.sort(list, new Comparator<Map.Entry<String, Integer> >() { 
            public int compare(Map.Entry<String, Integer> o1,  
                               Map.Entry<String, Integer> o2) 
            { 
                return (o1.getValue()).compareTo(o2.getValue()); 
            } 
        }); 
          
        // put data from sorted list to hashmap  
        HashMap<String, Integer> temp = new LinkedHashMap<String, Integer>(); 
        for (Map.Entry<String, Integer> aa : list) { 
            temp.put(aa.getKey(), aa.getValue()); 
        } 
        return temp; 
    } 
    
    
public static void main(String args[])
    {
        FastReader input=new FastReader();
        
        int n = input.nextInt();
        String s = input.next();
        char c[] = new char[n];
        int count =0;
        int flag=0;
        int l=1;
        for(int i=1;i<n;i=i+2)
        {
        	if(s.charAt(i)=='a')
        	{
        		c[l] = s.charAt(i);
        		
        		if(s.charAt(i-1)=='b')
        		{
        			c[l-1] = s.charAt(i-1);
        			l++;
        		}
        		else
        		{
        			c[l-1] = 'b';
        			l++;
        			count++;
        		}
        		l++;
        	}
        	else
        	{
        		c[l] = s.charAt(i);
        		
        		if(s.charAt(i-1)=='a')
        		{
        			c[l-1] = s.charAt(i-1);
        			l++;
        		}
        		else
        		{
        			c[l-1] = 'a';
        			l++;
        			count++;
        		}
        		l++;
        	}
        }
        System.out.println(count);
    	
       
        	for(int i=0;i<c.length;i++)
        	{
        		System.out.print(c[i]);
        	}
       
    
    }
            
static int gcd(int a, int b) 
{ 
  if (b == 0) 
    return a; 
  return gcd(b, a % b);  
} 
public static void sort(int arr[])
{
    int n = arr.length;
    int count =0;
    // One by one move boundary of unsorted subarray
    for (int i = 0; i < n-1; i++)
    {
        // Find the minimum element in unsorted array
        int min_idx = i;
        for (int j = i+1; j < n; j++)
            if (arr[j] < arr[min_idx])
                min_idx = j;

        // Swap the found minimum element with the first
        // element
        if(min_idx!=i)
        {
        	int temp = arr[min_idx];
        
        arr[min_idx] = arr[i];
        arr[i] = temp;
        count++;
        }
        }
    System.out.println(count);
}
   
public static int even_element(int b[],int n)
{
	int c[] = new int[n/2 + 1];
	int l=0;
	for(int i=1;i<n;i+=2)
	{
		c[l] = b[i];
		
		System.out.print(c[l] + " ");
		l++;
	}
	System.out.println();
	if(c.length!=1)
	{
		return even_element(c,n/2);
	}
	else
		return c[0];
}

  
    
    static boolean isPrime(int n) 
    { 
        // Corner case 
        if (n <= 1) 
            return false; 
  
        // Check from 2 to n-1 
        for (int i = 2; i < n; i++) 
            if (n % i == 0) 
                return false; 
  
        return true; 
    } 
 }
 
 
 class Pair
 {
     int a;
     int b;
     int c;
     Pair(int a,int b,int c)
     {
         this.a=a;
         this.b=b;
         this.c = c;
     }
 }