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.*;
import java.util.*;
public class Main {
    public static void main(String[] args) throws Exception {
        new Main().run();}

    static int groups = 0;
    static int[] fa;
    static int[] sz;

    static void init1(int n) {
        groups = n;
        fa = new int[n];
        for (int i = 1; i < n; ++i) {
            fa[i] = i;
        }
        sz = new int[n];
        Arrays.fill(sz, 1);
    }

    static int root(int p) {
        while (p != fa[p]) {
            fa[p] = fa[fa[p]];
            p = fa[p];
        }
        return p;
    }

    static void combine(int p, int q) {
        int i = root(p);
        int j = root(q);
        if (i == j) {
            return;
        }
        if (sz[i] < sz[j]) {
            fa[i] = j;
            sz[j] += sz[i];
        } else {
            fa[j] = i;
            sz[i] += sz[j];
        }
        groups--;
    }


    public static String roundS(double result, int scale){
        String fmt = String.format("%%.%df", scale);
        return String.format(fmt, result);
    }

    int[] unique(int a[]){
        int p = 1;
        for(int i=1;i<a.length;++i){
            if(a[i]!=a[i-1]){
                a[p++] = a[i];
            }
        }
        return Arrays.copyOf(a,p);
    }
    public static int eq_bigger(int[] a, int key) {
        return eq_bigger(a,0,a.length,key);
    }

    public static int eq_bigger(int[] a, int lo, int hi,
                                int key) {
        while (lo < hi) {
            int mid = (lo + hi) >>> 1;
            if (a[mid] < key) {
                lo = mid + 1;
            }else {
                hi = mid;
            }
        }
        return lo;
    }

    public static int bigger(int[] a, int key) {
        return bigger(a,0,a.length,key);
    }

    public static int bigger(int[] a, int lo, int hi,
                             int key) {
        while (lo < hi) {
            int mid = (lo + hi) >>> 1;
            if (a[mid] > key) {
                hi = mid;
            }else {
                lo = mid+1;
            }
        }
        return lo;
    }


    static int h[];
    static int to[];
    static int ne[];
    static int m = 0;

    public static void addEdge(int u, int v, int w) {
        to[++m] = v; ne[m] = h[u]; h[u] = m;
    }



    long w[];

    int cc = 0;

    void add(int u,int v,long ww) {
        to[++cc] = u;
        w[cc] = ww;
        ne[cc] = h[v];
        h[v] = cc;

        to[++cc] = v;
        w[cc] = ww;
        ne[cc] = h[u];
        h[u] = cc;
    }

    void solve() {

        int n = ni();
        int a =0;
        int b = 0;
 int an = 0;       String s = ns();
 StringBuilder y = new StringBuilder();
        for(int i=0;i<n;i+=2){
            char c =s.charAt(i);
            char c1 = s.charAt(i+1);
            if(c==c1){
                an++;
                y.append("ab");
            }else{
                y.append(c);
                y.append(c1);
            }

        }
        println(an);
        println(y);

    }


















































    static class S{
        int l = 0;
        int r = 0 ;
        int idx = 0;
        long all = 0;

        public S(int l,int r) {
            this.l = l;
            this.r = r;
        }
    }

    static S a[];
    static int[] o;

    static void init(int[] f){
        o = f;
        int len = o.length;
        a = new S[len*4];
        build(1,0,len-1);
    }

    static void build(int num,int l,int r){
        S cur = new S(l,r);
        if(l==r){
            a[num] = cur;
            a[num].all = o[l];
            a[num].idx = l;
            return;
        }else{
            int m = (l+r)>>1;
            int le = num<<1;
            int ri = le|1;
            build(le, l,m);
            build(ri, m+1,r);
            a[num] = cur;
            pushup(num, le, ri);
        }
    }



    static int[] query(int num,int l,int r){

        if(a[num].l>=l&&a[num].r<=r){
            return new int[]{a[num].idx,(int)a[num].all};
        }else{
            int m = (a[num].l+a[num].r)>>1;
            int le = num<<1;
            int ri = le|1;
            //   pushdown(num, le, ri);
            int ma = -1;
            int idx = 100000001;
            if(l<=m) {
                int r1[] = query(le, l, r);
                if(r1[1]>ma){
                    ma = r1[1];
                    idx = r1[0];
                }

            }
            if(r>m){
                int r2[] = query(ri, l, r);
                if(r2[1]>ma){
                    ma = r2[1];
                    idx = r2[0];
                }
            }
            return new int[]{idx,ma};
        }
    }


    static void update(int num,int l,long v){
        if(a[num].l==a[num].r){
            a[num].all = v;
        }else{
            int m = (a[num].l+a[num].r)>>1;
            int le = num<<1;
            int ri = le|1;
            pushdown(num, le, ri);
            if(l<=m){
                update(le,l,v);
            }
            if(l>m){
                update(ri,l,v);
            }
            pushup(num,le,ri);
        }
    }

    static void pushup(int num,int le,int ri){
        a[num].all = Math.max(a[le].all,a[ri].all);
        if(a[le].all>a[ri].all){
            a[num].idx = a[le].idx;
        }else{
            a[num].idx = a[ri].idx;
        }

    }
    static void pushdown(int num,int le,int ri){

    }


    int gcd(int a,int b){ return b==0?a: gcd(b,a%b);}
    InputStream is;PrintWriter out;
    void run() throws Exception {is = System.in;out = new PrintWriter(System.out);solve();out.flush();}
    private byte[] inbuf = new byte[1024];
    public int lenbuf = 0, ptrbuf = 0;
    private int readByte() {
        if (lenbuf == -1) throw new InputMismatchException();
        if (ptrbuf >= lenbuf) {
            ptrbuf = 0;
            try {lenbuf = is.read(inbuf);} catch (IOException e) {throw new InputMismatchException();}
            if (lenbuf <= 0) return -1;
        }
        return inbuf[ptrbuf++];}
    private boolean isSpaceChar(int c) {return !(c >= 33 && c <= 126);}
    private int skip() {int b;while((b = readByte()) != -1 && isSpaceChar(b));return b;}
    private double nd() {return Double.parseDouble(ns());}
    private char nc() {return (char) skip();}
    private char ncc() {int b;while((b = readByte()) != -1 && !(b >= 32 && b <= 126));return (char)b;}
    private String ns() {int b = skip();StringBuilder sb = new StringBuilder();
        while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != ' ')
            sb.appendCodePoint(b);b = readByte(); }
        return sb.toString();}
    private char[] ns(int n) {char[] buf = new char[n];int b = skip(), p = 0;
        while (p < n && !(isSpaceChar(b))) { buf[p++] = (char) b;b = readByte(); }
        return n == p ? buf : Arrays.copyOf(buf, p);}
    private String nline() {int b = skip();StringBuilder sb = new StringBuilder();
        while (!isSpaceChar(b) || b == ' ') { sb.appendCodePoint(b);b = readByte(); }
        return sb.toString();}
    private char[][] nm(int n, int m) {char[][] a = new char[n][];for (int i = 0; i < n; i++) a[i] = ns(m);return a;}
    private int[] na(int n) {int[] a = new int[n];for (int i = 0; i < n; i++) a[i] = ni();return a;}
    private long[] nal(int n) { long[] a = new long[n];for (int i = 0; i < n; i++) a[i] = nl();return a;}
    private int ni() { int num = 0, b; boolean minus = false;
        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')){};
        if (b == '-') { minus = true; b = readByte(); }
        while (true) {
            if (b >= '0' && b <= '9') num = (num << 3) + (num << 1) + (b - '0');
            else return minus ? -num : num;
            b = readByte();}}
    private long nl() { long num = 0; int b;
        boolean minus = false;
        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')){};
        if (b == '-') { minus = true; b = readByte(); }
        while (true) {
            if (b >= '0' && b <= '9')  num = num * 10 + (b - '0');
            else return minus ? -num : num;
            b = readByte();}}
    void print(Object obj){out.print(obj);}
    void println(Object obj){out.println(obj);}
    void println(){out.println();}
}