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