#include <bits/stdc++.h>
const int MOD = 1e9 + 7;
const int v1 = 1e5 + 5;
using namespace std;
long long gcd(unsigned long long a, unsigned long long b) {
  if (a == 0) return b;
  return gcd(b % a, a);
}
long long lcm(long long a, long long b) { return a * b / gcd(a, b); }
bool sqpf(long double x) {
  long double sr = sqrt(x);
  return ((sr - floor(sr)) == 0);
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n = 0;
  cin >> n;
  string s;
  cin >> s;
  string ans;
  for (long long i = 0; i < s.length() - 1; i++) {
    if (s[i] != s[i + 1]) {
      ans += s[i];
      ans += s[i + 1];
      i++;
    }
  }
  cout << n - ans.length() << "\n";
  cout << ans << '\n';
}
