#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string str;
  cin >> str;
  for (int i = 0;; i += 2) {
    if (i >= str.length() - 1) break;
    if (str[i] == str[i + 1]) {
      str.erase(str.begin() + i);
      i -= 2;
    }
  }
  if (str.length() % 2) str.erase(str.end() - 1);
  cout << n - str.length() << endl;
  cout << str << endl;
}
