#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long n;
  string s;
  cin >> n >> s;
  if (n == 0) {
    cout << "0" << endl << "";
  }
  string s1;
  long long i = 0;
  char temp = '#';
  while (i < n) {
    if (s[i] == temp && s1.size() % 2 != 0) {
      i++;
    } else {
      s1.push_back(s[i]);
      temp = s[i];
      i++;
    }
  }
  if (s1.size() & 1) {
    s1 = s1.substr(0, s1.size() - 1);
  }
  cout << s.size() - s1.size() << endl;
  cout << s1 << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  long long test = 1;
  while (test--) {
    solve();
  }
  return 0;
}
