#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  string S;
  cin >> S;
  string A = "";
  for (int i = 0; i < N - 1; ++i) {
    if (S[i] != S[i + 1]) {
      A += S[i];
      A += S[i + 1];
      i++;
    }
  }
  cout << N - A.length() << endl << A;
}
