#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, c = 0, b = 0;
  string s;
  vector<char> a;
  cin >> n >> s;
  for (int i = 0; i < n; i = i + 2) {
    if (i == n - 1 && i % 2 == b % 2) break;
    if (s[i] != s[i + 1]) {
      c = c + 2;
      a.push_back(s[i]);
      a.push_back(s[i + 1]);
    } else {
      i--;
      b++;
    }
  }
  cout << n - c << endl;
  for (int i = 0; i < a.size(); i++) cout << a[i];
}
