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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) throws IOException {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader sc = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, sc, out);
        out.close();
    }

    static class Task {
        public void solve(int testNumber, InputReader sc, PrintWriter out) throws IOException {
        	int n=sc.nextInt();
        	char[] res=(" "+sc.next()).toCharArray();
        	int cnt=0;
        	
        	for(int i=1;i<=n;i+=2) {
        		if(res[i]==res[i+1]) {
        			cnt++;
        			res[i+1]=res[i]=='a'?'b':'a';
        		}
        	}
        	out.println(cnt);
        	for(int i=1;i<=n;i++)
        		out.print(res[i]);
        }
    }

    static class InputReader {
        private InputStreamReader reader;
        private char[] buf;
        private int len, now;
     
        public InputReader(InputStream stream) {
            reader = new InputStreamReader(stream);
            buf = new char[1024];
            len = 0;
            now = 0;
        }
     
        public String next() throws IOException {
            if (!hasNext()) throw new NullPointerException();
            StringBuilder sb = new StringBuilder();
            while (!isSpaceChar(buf[now])) {
                sb.append(buf[now]);
                if (!move()) break;
            }
            return sb.toString();
        }
     
        public int nextInt() throws IOException {
            if (!hasNext()) throw new NullPointerException();
            boolean x = false;
            if (buf[now] == '-') {
                x = true;
                if (!move()) throw new NumberFormatException();
            }
            int ans = 0;
            while (!isSpaceChar(buf[now])) {
                if (isNum(buf[now])) ans = ans * 10 + buf[now] - '0';
                else throw new NumberFormatException();
                if (!move()) break;
            }
            return (x ? -1 : 1) * ans;
        }
     
        public String nextLine() throws IOException {
            if (!hasNextLine()) throw new NullPointerException();
            StringBuilder sb = new StringBuilder();
            while (buf[now] != '\n') {
                sb.append(buf[now]);
                if (!move()) return sb.toString();
            }
            now++;
            return sb.toString();
        }
     
        public long nextLong() throws IOException {
            if (!hasNext()) throw new NullPointerException();
            boolean x = false;
            if (buf[now] == '-') {
                x = true;
                if (!move()) throw new NumberFormatException();
            }
            long ans = 0;
            while (!isSpaceChar(buf[now])) {
                if (isNum(buf[now])) ans = ans * 10 + buf[now] - '0';
                else throw new NumberFormatException();
                if (!move()) break;
            }
            return (x ? -1 : 1) * ans;
        }
     
        public double nextDouble() throws IOException {
            return Double.parseDouble(next());
        }
     
        public int nextHexInt() throws IOException {
            if (!hasNext()) throw new NullPointerException();
            boolean x = false;
            if (buf[now] == '-') {
                x = true;
                if (!move()) throw new NumberFormatException();
            }
            int ans = 0;
            while (!isSpaceChar(buf[now])) {
                if (isHex(buf[now])) ans = ans * 16 + toHex(buf[now]);
                else throw new NumberFormatException();
                if (!move()) break;
            }
            return (x ? -1 : 1) * ans;
        }
     
        public char nextChar() throws IOException {
            if (!hasNext()) throw new NullPointerException();
            char tmp = buf[now];
            move();
            return tmp;
        }
        public int next(char[] s) throws IOException {
            if (!hasNext()) throw new NullPointerException();
            int len=0;
            while (!isSpaceChar(buf[now])&&len<s.length) {
                s[len++]=buf[now];
                if (!move()) break;
            }
            return len;
        }
        public boolean hasNext() throws IOException {
            return skip();
        }
     
        public boolean hasNextLine() throws IOException {
            return now < len || refill();
        }
     
        private boolean move() throws IOException {
            now++;
            return hasNextLine();
        }
     
        private boolean skip() throws IOException {
            if (!hasNextLine()) return false;
            while (isSpaceChar(buf[now])) {
                if (!move()) return false;
            }
            return true;
        }
     
        private boolean isSpaceChar(char c) {
            return !(c >= 33 && c <= 126);
        }
     
        private boolean isNum(char c) {
            return c >= '0' && c <= '9';
        }
     
        private boolean isHex(char c) {
            return c >= '0' && c <= '9' || c >= 'A' && c <= 'F';
        }
     
        private int toHex(char c) {
            if (c >= '0' && c <= '9') return c - '0';
            else return c - 'A' + 10;
        }
     
        private boolean refill() throws IOException {
            len = reader.read(buf);
            now = 0;
            return len > 0;
        }
    }
}