#include <bits/stdc++.h>
using namespace std;
struct trp {
  int x, y, z;
};
void fun() {}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int n;
  cin >> n;
  string s;
  cin >> s;
  string a;
  for (long long int i = 0; i < n; i++) {
    if (a.empty()) a += s[i];
    if ((a.size()) % 2 == 0)
      a += s[i];
    else {
      if (a.back() != s[i]) a += s[i];
    }
  }
  if (a.size() & 1) a.pop_back();
  cout << n - a.size() << endl;
  if ((n - a.size()) != n) {
    cout << a;
  }
}
