#include <bits/stdc++.h>
using namespace std;
long long n, ans;
string str;
long long solve() {
  cin >> n >> str;
  long long i = 0;
  while (1) {
    if (str[i] != str[i + 1]) {
      i += 2;
    } else {
      str.erase(str.begin() + i + 1);
    }
    if (i >= str.length()) break;
  }
  if (str.length() % 2) str.erase(str.end() - 1);
  cout << n - str.length() << "\n" << str;
  return 0;
}
signed main() {
  ios::sync_with_stdio(0);
  long long t = 1;
  while (t--) solve();
  return 0;
}
