#include <bits/stdc++.h>
using namespace std;
void clear(queue<char> &q) {
  queue<char> empty;
  swap(empty, q);
}
int main() {
  int n, changed = 0;
  char word[2] = {'a', 'b'};
  scanf("%d\n", &n);
  char s[n + 1];
  vector<char> _after;
  queue<char> q;
  for (int i = 0; i < n; i++) {
    scanf("%c", &s[i]);
    q.push(s[i]);
    if (i > 0 && i % 2 != 0) {
      if (q.front() == q.back()) {
        for (int j = 0; j < 2; j++) {
          if (q.front() != word[j]) {
            q.pop();
            q.push(word[j]);
            changed++;
          }
        }
      }
      _after.push_back(q.front());
      _after.push_back(q.back());
      clear(q);
    }
  }
  cout << changed << endl;
  for (int i = 0; i < _after.size(); i++) {
    cout << _after[i];
  }
}
