#include <bits/stdc++.h>
using namespace std;
ifstream first("test.in");
ofstream g("test.out");
char second[200005];
long long n, ans;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> second[i];
  for (int i = 1; i <= n; i += 2) {
    if (second[i] == second[i + 1]) {
      if (second[i + 1] == 'a')
        second[i + 1] = 'b';
      else
        second[i + 1] = 'a';
      ans++;
    }
  }
  cout << ans << '\n';
  for (int i = 1; i <= n; i++) cout << second[i];
  return 0;
}
