#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  string s;
  string ans;
  cin >> n;
  cin >> s;
  for (int i = 0; i < n; i++) {
    if (ans.size() % 2 == 0 || ans.back() != s[i]) ans.push_back(s[i]);
  }
  if (ans.size() % 2 == 1) ans.pop_back();
  cout << n - ans.size() << "\n";
  cout << ans;
}
