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.util.*;
import java.io.*;

public class Es1
{
    static IO io = new IO();
    public static void main(String[] args)
    {
		int n = io.getInt();
		String s = io.getWord();
		int countA = 0, countB = 0;
		int count = 0;
		
		for(int i=0; i<n; i+=2)
		{
			if(s.charAt(i)=='a')
				countA++;
			else
				countB++;
			if(s.charAt(i+1)=='a')
				countA++;
			else
				countB++;
			
			if(countA != countB){
					count++;
					countA = countB;
					//tmp = "ab";
			}
			
			//ans.append(tmp);
			
		}
		io.println(count);
		for(int i=0; i<n; i+=2){
			if(s.charAt(i)=='a')
				io.print("ab");
			else
				io.print("ba");
		}
		io.println();
        io.close();
    }
}



class IO extends PrintWriter {
	public IO() {
        super(new BufferedOutputStream(System.out));
        r = new BufferedReader(new InputStreamReader(System.in));
    }

    public IO(String fileName) {
        super(new BufferedOutputStream(System.out));
        try{
            r = new BufferedReader(new FileReader(fileName));
        } catch (FileNotFoundException e) {
            this.println("File Not Found");
        }
    }

    public boolean hasMoreTokens() {
        return peekToken() != null;
    }

    public int getInt() {
        return Integer.parseInt(nextToken());
    }

    public double getDouble() {
        return Double.parseDouble(nextToken());
    }

    public long getLong() {
        return Long.parseLong(nextToken());
    }

    public String getWord() {
        return nextToken();
    }

	public String getLine(){
        try{
            st = null;
            return r.readLine();
        }
        catch(IOException ex){}
        return null;
    }
	

    private BufferedReader r;
    private String line;
    private StringTokenizer st;
    private String token;

    private String peekToken() {
        if (token == null)
            try {
                while (st == null || !st.hasMoreTokens()) {
                    line = r.readLine();
                    if (line == null) return null;
                    st = new StringTokenizer(line);
                }
                token = st.nextToken();
            } catch (IOException e) { }
        return token;
    }

    private String nextToken() {
        String ans = peekToken();
        token = null;
        return ans;
    }
}