#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long n;
  cin >> n;
  string s;
  cin >> s;
  long long p1 = 0;
  long long p2 = 1;
  string ans;
  for (long long i = 0; i < s.size() && p1 < s.size() && p2 < s.size(); i++) {
    if (s[p1] == s[p2]) {
      p2++;
    } else {
      ans.push_back(s[p1]);
      ans.push_back(s[p2]);
      p1 = p2 + 1;
      p2 = p1 + 1;
    }
  }
  if (p1 == s.size() - 1) ans.push_back(s[p1]);
  if (ans.size() % 2 == 1) ans.pop_back();
  cout << s.size() - ans.size() << endl;
  cout << ans << endl;
  return 0;
}
