#include <bits/stdc++.h>
using namespace std;
string s, stringg;
int main() {
  int t;
  cin >> t;
  cin >> s;
  for (int i = 0; i < t - 1; i += 2) {
    if (s[i] != s[i + 1]) {
      stringg += s[i];
      stringg += s[i + 1];
    } else
      i--;
  }
  cout << t - stringg.size() << endl;
  cout << stringg << endl;
  return 0;
}
